'I find this handy to use in logins scripts.
'Feed the function the name of the group you want to check for membership of, it will return true if is member
'Example:
   if memberOf("Fred's Friends") then msgbox "Fred says hello!"

function memberOf(groupName)
   set oNet = CreateObject("WScript.Network")
   set oUser = GetObject("WinNT://YourDomainName/" & oNet.UserName & ",user")
   
   ' Enurmerate Groups for the user
   for each oGroup in oUser.Groups
      if ucase(oGroup.Name) = ucase(groupName) then
         memberOf = true
         exit for
      end if
   next
   
   set oUser = nothing
   set oGroup = nothing
   set onet = nothing
end function