actually you can, sysreset has all of their addons setup like that. Example to follow. It will run as a valid script and you can use $readini on it, never tried to writeini or anything else though.

Code:
/*
[Addon]
Script=Script name
Version=beta
Author=pball
Desc=
For=Mirc
Date=today

[script]
*/
;Script goes here

http://scripting.pball.win
My personal site with some scripts I've released.