Access AD Primary Group using PowerShell 2.0

[DTracy]

We have a Server 2003 LAN with XP-Pro, Vista, and Win-7 workstations. Currently my login script is written using vbscript and controls drive mapping, printer mapping, and proxy server connections. We are considering a move to Server 2012 with XP-Pro, Vista, and Win-7 workstations and I have been unable to determine what changes are needed to the vbscript to make it compatible with everything, so I'm trying to learn PowerShell to re-write the script. So far I can map a drive and printer but am unable to determine the user’s primary group as I use it for a mapping branch. My workstation is XP and I have installed PowerShell 2.0 for my testing. All the examples I have located via Google use get-qaduser, get-qadgroup cmdlets which PowerShell complains about being incompatible with my 2.0.

Is there a compatible way to find the user's Primary Group using PowerShell 2.0?

Thanks and regards,
David.