I've written a small stand alone script to list the users of a group. If anyone is interested I can clean it up and release it as either an IIP pal or a stand alone script. It's working for 6.1.0 at the moment but can easily be altered to work with 6.2/6.3 I think.
I'm not sure if anyone else has any use of this, so I thought I'd ask before spending time on releasing it as a mod.