Defining my own command

I'm trying to define my own command in MacVim to turn a c statement or range of statements into comments. So I put this in my vimrc:开发者_StackOverflow

command -range Com :<line1>,<line2>s?^.*$?/*&*/?

It works fine if I just enter :Com to comment the current line. But if I enter something like :Com 3 5 in order to turn lines 3 thru 5 into comments I always get this error message:

E488: Trailing characters

Can anyone help?

You need to provide the range before the command, like that:

:3,5Com

Anyway, I suggest you to check the NERD_commenter plugin. It's great for commenting source code.