diff --git a/src/ex_cmds.h b/src/ex_cmds.h
index fcf15ba..c2657b0 100644
--- a/src/ex_cmds.h
+++ b/src/ex_cmds.h
@@ -57,6 +57,7 @@
 				// buffer when curbuf_lock is set
 #define EX_NONWHITE_OK 0x2000000  // command can be followed by non-white
 #define EX_KEEPSCRIPT  0x4000000  // keep sctx of where command was invoked
+#define EX_EXPR_ARG    0x8000000  // argument is an expression
 
 #define EX_FILES (EX_XFILE | EX_EXTRA)	// multiple extra files allowed
 #define EX_FILE1 (EX_FILES | EX_NOSPC)	// 1 file, defaults to current file
@@ -265,7 +266,7 @@
 	EX_RANGE|EX_WORD1|EX_TRLBAR,
 	ADDR_OTHER),
 EXCMD(CMD_caddexpr,	"caddexpr",	ex_cexpr,
-	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM,
+	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM|EX_EXPR_ARG,
 	ADDR_NONE),
 EXCMD(CMD_caddfile,	"caddfile",	ex_cfile,
 	EX_TRLBAR|EX_FILE1,
@@ -274,7 +275,7 @@
 	EX_RANGE|EX_COUNT|EX_TRLBAR,
 	ADDR_UNSIGNED),
 EXCMD(CMD_call,		"call",		ex_call,
-	EX_RANGE|EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_RANGE|EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_LINES),
 EXCMD(CMD_catch,	"catch",	ex_catch,
 	EX_EXTRA|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
@@ -307,7 +308,7 @@
 	EX_TRLBAR|EX_RANGE|EX_WHOLEFOLD|EX_EXTRA|EX_CMDWIN|EX_LOCK_OK|EX_MODIFY,
 	ADDR_LINES),
 EXCMD(CMD_cexpr,	"cexpr",	ex_cexpr,
-	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM|EX_BANG,
+	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM|EX_EXPR_ARG|EX_BANG,
 	ADDR_NONE),
 EXCMD(CMD_cfile,	"cfile",	ex_cfile,
 	EX_TRLBAR|EX_FILE1|EX_BANG,
@@ -325,7 +326,7 @@
 	EX_RANGE|EX_WORD1|EX_TRLBAR,
 	ADDR_OTHER),
 EXCMD(CMD_cgetexpr,	"cgetexpr",	ex_cexpr,
-	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM,
+	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM|EX_EXPR_ARG,
 	ADDR_NONE),
 EXCMD(CMD_chdir,	"chdir",	ex_cd,
 	EX_BANG|EX_FILE1|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
@@ -409,7 +410,7 @@
 	EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_const,	"const",	ex_let,
-	EX_EXTRA|EX_BANG|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_BANG|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_copen,	"copen",	ex_copen,
 	EX_RANGE|EX_COUNT|EX_TRLBAR,
@@ -526,28 +527,28 @@
 	EX_TRLBAR|EX_EXTRA|EX_NOSPC|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_echo,		"echo",		ex_echo,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_echoerr,	"echoerr",	ex_execute,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_echohl,	"echohl",	ex_echohl,
 	EX_EXTRA|EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_echomsg,	"echomsg",	ex_execute,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_echoconsole,	"echoconsole",	ex_execute,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_echon,	"echon",	ex_echo,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_else,		"else",		ex_else,
 	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_elseif,	"elseif",	ex_else,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_emenu,	"emenu",	ex_emenu,
 	EX_NEEDARG|EX_EXTRA|EX_TRLBAR|EX_NOTRLCOM|EX_RANGE|EX_CMDWIN|EX_LOCK_OK,
@@ -586,19 +587,19 @@
 	EX_EXTRA|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_eval,		"eval",		ex_eval,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_ex,		"ex",		ex_edit,
 	EX_BANG|EX_FILE1|EX_CMDARG|EX_ARGOPT|EX_TRLBAR,
 	ADDR_NONE),
 EXCMD(CMD_execute,	"execute",	ex_execute,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_exit,		"exit",		ex_exit,
 	EX_RANGE|EX_WHOLEFOLD|EX_BANG|EX_FILE1|EX_ARGOPT|EX_DFLALL|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_LINES),
 EXCMD(CMD_export,	"export",	ex_export,
-	EX_EXTRA|EX_NOTRLCOM|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_exusage,	"exusage",	ex_exusage,
 	EX_TRLBAR,
@@ -649,7 +650,7 @@
 	EX_RANGE|EX_BANG|EX_WHOLEFOLD|EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_LINES),
 EXCMD(CMD_for,		"for",		ex_while,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_function,	"function",	ex_function,
 	EX_EXTRA|EX_BANG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
@@ -709,7 +710,7 @@
 	EX_EXTRA|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_if,		"if",		ex_if,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_ijump,	"ijump",	ex_findpat,
 	EX_BANG|EX_RANGE|EX_DFLALL|EX_WHOLEFOLD|EX_EXTRA,
@@ -799,7 +800,7 @@
 	EX_EXTRA|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_laddexpr,	"laddexpr",	ex_cexpr,
-	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM,
+	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM|EX_EXPR_ARG,
 	ADDR_NONE),
 EXCMD(CMD_laddbuffer,	"laddbuffer",	ex_cbuffer,
 	EX_RANGE|EX_WORD1|EX_TRLBAR,
@@ -847,10 +848,10 @@
 	EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM,
 	ADDR_NONE),
 EXCMD(CMD_let,		"let",		ex_let,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_lexpr,	"lexpr",	ex_cexpr,
-	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM|EX_BANG,
+	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM|EX_EXPR_ARG|EX_BANG,
 	ADDR_NONE),
 EXCMD(CMD_legacy,	"legacy",	ex_wrongmodifier,
 	EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM|EX_CMDWIN|EX_LOCK_OK,
@@ -871,7 +872,7 @@
 	EX_RANGE|EX_WORD1|EX_TRLBAR,
 	ADDR_OTHER),
 EXCMD(CMD_lgetexpr,	"lgetexpr",	ex_cexpr,
-	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM,
+	EX_NEEDARG|EX_WORD1|EX_NOTRLCOM|EX_EXPR_ARG,
 	ADDR_NONE),
 EXCMD(CMD_lgrep,	"lgrep",	ex_make,
 	EX_RANGE|EX_BANG|EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM|EX_TRLBAR|EX_XFILE,