The ToCommandLine operation sends command text to the command line without executing the command(s). However, sometimes you want command text to be printed into the history, from within a user function. You can use print for this, but this doesn't appear as an issued command. For this to happen (such that you can press "up" to scroll between commands) you have to prefix the print with a special character. This character is different on windows and on Mac. The following function prints commands to the history, on Mac and Windows. It works on an English charset, not sure about others.

Function cmdToHistory(cmd)	// returns 0 if Macintosh, 1 if Windows
	string cmd
	String platform= UpperStr(igorinfo(2))
	strswitch(platform)
		case "MACINTOSH":
			print num2char(-91) + cmd
		break
		case "WINDOWS":
			print num2char(-107)+cmd
		break
	endswitch
End