diff --git a/src/evalfunc.c b/src/evalfunc.c
index 8943a30..4c9ee4c 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -1058,6 +1058,7 @@
 static argcheck_T arg2_string_number[] = {arg_string, arg_number};
 static argcheck_T arg2_string_or_list_dict[] = {arg_string_or_list_any, arg_dict_any};
 static argcheck_T arg2_string_or_list_bool[] = {arg_string_or_list_any, arg_bool};
+static argcheck_T arg2_string_or_list_number[] = {arg_string_or_list_any, arg_number};
 static argcheck_T arg2_string_string_or_number[] = {arg_string, arg_string_or_nr};
 static argcheck_T arg3_any_list_dict[] = {NULL, arg_list_any, arg_dict_any};
 static argcheck_T arg3_buffer_lnum_lnum[] = {arg_buffer, arg_lnum, arg_lnum};
@@ -1774,7 +1775,7 @@
 			ret_number,	    f_char2nr},
     {"charclass",	1, 1, FEARG_1,	    arg1_string,
 			ret_number,	    f_charclass},
-    {"charcol",		1, 1, FEARG_1,	    arg1_string_or_list_any,
+    {"charcol",		1, 2, FEARG_1,	    arg2_string_or_list_number,
 			ret_number,	    f_charcol},
     {"charidx",		2, 3, FEARG_1,	    arg3_string_number_bool,
 			ret_number,	    f_charidx},
@@ -1784,7 +1785,7 @@
 			ret_number,	    f_cindent},
     {"clearmatches",	0, 1, FEARG_1,	    arg1_number,
 			ret_void,	    f_clearmatches},
-    {"col",		1, 1, FEARG_1,	    arg1_string_or_list_any,
+    {"col",		1, 2, FEARG_1,	    arg2_string_or_list_number,
 			ret_number,	    f_col},
     {"complete",	2, 2, FEARG_2,	    arg2_number_list,
 			ret_void,	    f_complete},
@@ -3389,12 +3390,31 @@
 {
     colnr_T	col = 0;
     pos_T	*fp;
-    int		fnum = curbuf->b_fnum;
+    switchwin_T	switchwin;
+    int		winchanged = FALSE;
 
-    if (in_vim9script()
-	    && check_for_string_or_list_arg(argvars, 0) == FAIL)
+    if (check_for_string_or_list_arg(argvars, 0) == FAIL
+	    || check_for_opt_number_arg(argvars, 1) == FAIL)
 	return;
 
+    if (argvars[1].v_type != VAR_UNKNOWN)
+    {
+	tabpage_T	*tp;
+	win_T		*wp;
+
+	// use the window specified in the second argument
+	wp = win_id2wp_tp((int)tv_get_number(&argvars[1]), &tp);
+	if (wp == NULL || tp == NULL)
+	    return;
+
+	if (switch_win_noblock(&switchwin, wp, tp, TRUE) != OK)
+	    return;
+
+	check_cursor();
+	winchanged = TRUE;
+    }
+
+    int fnum = curbuf->b_fnum;
     fp = var2fpos(&argvars[0], FALSE, &fnum, charcol);
     if (fp != NULL && fnum == curbuf->b_fnum)
     {
@@ -3427,6 +3447,9 @@
 	}
     }
     rettv->vval.v_number = col;
+
+    if (winchanged)
+	restore_win_noblock(&switchwin, TRUE);
 }
 
 /*
diff --git a/src/testdir/test_cursor_func.vim b/src/testdir/test_cursor_func.vim
index d2685ed..a48db15 100644
--- a/src/testdir/test_cursor_func.vim
+++ b/src/testdir/test_cursor_func.vim
@@ -287,8 +287,9 @@
 
 " Test for the charcol() function
 func Test_charcol()
-  call assert_fails('call charcol({})', 'E731:')
-  call assert_equal(0, charcol(0))
+  call assert_fails('call charcol({})', 'E1222:')
+  call assert_fails('call charcol(".", [])', 'E1210:')
+  call assert_fails('call charcol(0)', 'E1222:')
   new
   call setline(1, ['', "01\tà4è678", 'Ⅵ', '012345678'])
 
@@ -344,6 +345,25 @@
   call assert_equal([1, 10, 2, 10, 7], g:InsertCurrentCol)
   iunmap <F3>
 
+  " Test for getting the column number in another window.
+  let winid = win_getid()
+  new
+  call win_execute(winid, 'normal 1G')
+  call assert_equal(1, charcol('.', winid))
+  call assert_equal(1, charcol('$', winid))
+  call win_execute(winid, 'normal 2G6l')
+  call assert_equal(7, charcol('.', winid))
+  call assert_equal(10, charcol('$', winid))
+
+  " calling from another tab page also works
+  tabnew
+  call assert_equal(7, charcol('.', winid))
+  call assert_equal(10, charcol('$', winid))
+  tabclose
+
+  " unknown window ID
+  call assert_equal(0, charcol('.', 10001))
+
   %bw!
 endfunc
 
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 131db10..d0508ce 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -1484,7 +1484,8 @@
   call assert_equal(0, col([1, 100]))
   call assert_equal(0, col([1]))
   call assert_equal(0, col(test_null_list()))
-  call assert_fails('let c = col({})', 'E731:')
+  call assert_fails('let c = col({})', 'E1222:')
+  call assert_fails('let c = col(".", [])', 'E1210:')
 
   " test for getting the visual start column
   func T()
@@ -1514,6 +1515,15 @@
   call assert_equal(4, col('.'))
   set virtualedit&
 
+  " Test for getting the column number in another window
+  let winid = win_getid()
+  new
+  call win_execute(winid, 'normal 1G$')
+  call assert_equal(3, col('.', winid))
+  call win_execute(winid, 'normal 2G')
+  call assert_equal(8, col('$', winid))
+  call assert_equal(0, col('.', 5001))
+
   bw!
 endfunc
 
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index 10ae2ee..ecbfeac 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -687,6 +687,7 @@
 def Test_charcol()
   v9.CheckDefAndScriptFailure(['charcol(10)'], ['E1013: Argument 1: type mismatch, expected string but got number', 'E1222: String or List required for argument 1'])
   v9.CheckDefAndScriptFailure(['charcol({a: 10})'], ['E1013: Argument 1: type mismatch, expected string but got dict<number>', 'E1222: String or List required for argument 1'])
+  v9.CheckDefAndScriptFailure(['charcol(".", [])'], ['E1013: Argument 2: type mismatch, expected number but got list<unknown>', 'E1210: Number required for argument 2'])
   v9.CheckDefExecAndScriptFailure(['charcol("")'], 'E1209: Invalid value for a line number')
   new
   setline(1, ['abcdefgh'])
@@ -734,6 +735,7 @@
   v9.CheckDefAndScriptFailure(['col(10)'], ['E1013: Argument 1: type mismatch, expected string but got number', 'E1222: String or List required for argument 1'])
   v9.CheckDefAndScriptFailure(['col({a: 10})'], ['E1013: Argument 1: type mismatch, expected string but got dict<number>', 'E1222: String or List required for argument 1'])
   v9.CheckDefAndScriptFailure(['col(true)'], ['E1013: Argument 1: type mismatch, expected string but got bool', 'E1222: String or List required for argument 1'])
+  v9.CheckDefAndScriptFailure(['col(".", [])'], ['E1013: Argument 2: type mismatch, expected number but got list<unknown>', 'E1210: Number required for argument 2'])
   v9.CheckDefExecAndScriptFailure(['col("")'], 'E1209: Invalid value for a line number')
   bw!
 enddef
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index 5a17880..faaa915 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -53,7 +53,7 @@
       assert_equal(function('len'), Res)
 
       var RetOne: func(string): number = function('len')
-      var RetTwo: func(string): number = function('charcol')
+      var RetTwo: func(string): number = function('strlen')
       var RetThat: func = g:atrue ? RetOne : RetTwo
       assert_equal(function('len'), RetThat)
 
diff --git a/src/version.c b/src/version.c
index 8e97025..64ed648 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    863,
+/**/
     862,
 /**/
     861,