Script for adding users to file permissions

I need a script to add the following two users ids to the permissions for various files: IIS_WPG and IUSR_CowGirl. I am fairly familiar with scripting but haven't been able to figure out how to do this via a script. Manually doing it is slow. I don't want to create users but only add them to a files permission list.

thanks in advance

How have you been adding them? Are you using ACLs or ordinary permissions?

I have been manually adding them to each file I move from my PC to my server via windows properties