in reply to
Win32 Sample Code for checking if a user is in the group "Power Users" on a Windows (XP) machine?
An additional module you can use is Win32::OLE for tapping into the Windows Management Interface (WMI).
As for providing sample code.. it wouldn't be very kind of you to ask for code without providing some of your own first. Might I suggest using a search engine, such as Google, to search for the terms 'perl', 'wmi', and 'groups'. There are tons of examples out there.
If you're really stuck, check out Microsoft's Scriptomatic. It can create the code you're looking for, and will even do it in Perl!