Add/Remove users membership to groups remotely -win2k

Hi
I want to add an Active Directory group to a group of Local
Administrators on 200 local machines. For example, in the domain
"test1", add group called "test1\local-admin" to "Administrators"
group on every computer in the domain. I found a script:

'adduser.vbs
'adds a user or group to a group
Set objGroup = GetObject("WinNT://" & Wscript.Arguments(0) & "/" & _
Wscript.Arguments(1))

objGroup.add "WinNT://" & Wscript.Arguments(0) & "/" & _
Wscript.Arguments(2)


but that only works on users and only local users - not domain users.
If you have any ideas on how to do this, I'd really appreciate it.
Thank you very much.

Mike Gorn.