How to use the PrimaryGroupID attribute to find the primary group for a user

'
' The following VBS code illustrates how to determine the primary group
' given an ADsPath as a single argument. The script determines if the
' string passed is a WinNT or LDAP path and then uses the appropriate
' method for retrieving the Primary Group path.
'
' ADsSecurity Constants
'
const ADS_SID_RAW         = 0
const ADS_SID_HEXSTRING  = 1
const ADS_SID_SAM         = 2
const ADS_SID_UPN         = 3
const ADS_SID_SDDL        = 4
const ADS_SID_WINNT_PATH  = 5
const ADS_SID_ACTIVE_DIRECTORY_PATH = 6
const ADS_SID_SID_BINDING = 7
'-------------------------------------------------
' Function StrRID returns and unsigned long of
' the given RID value
' 
' If the most significant bit is set in a VB Long
' then VB will interpret the value as a negative number
' and CStr will convert the unsigned long into a string with a leading
' "-" sign.
'
' This function checks to see if the most significant bit
' is set, then tricks the CStr function into outputting
' and unsigned long value by using a double float value
' to store the RID value, then uses the CStr function to get the
' string version.
'
function StrRID( inVal )
  dim dLocal
  if( (inVal and &H80000000) <> 0 ) then
    dLocal = CDbl((inval and &H7FFFFFFF))
    dLocal = dLocal + 2^31
    StrRID = cstr(dLocal)
  else
    StrRID = Cstr(inVal)
  end if
end function
'=================================================
' Main Script
'
' Assumes that the first argument is a WinNT or
' LDAP user path
'
set args = WScript.Arguments
WScript.Echo "Start: "& Now
set ADsSid = CreateObject("ADsSID")
'
' Determine if we are using the LDAP or WinNT providers
'
userAdsPath = args(0)
if( InStr(userAdsPath,"LDAP") <> 0 ) then
  '
  ' LDAP ADS Path, need to work with the an Active Directory Path
  '
  ADS_SID_Constant = ADS_SID_ACTIVE_DIRECTORY_PATH
else
  '
  ' WinNT Path, working with the WinNT provider
  '
  ADS_SID_Constant = ADS_SID_WINNT_PATH
end if
'  
' Initialize the IADsSID object and retrieve
' the SDDL form of the SID
'
ADsSID.SetAs ADS_SID_Constant, CStr(userADsPath)
DomainSID = ADsSID.GetAs(ADS_SID_SDDL)
'
' We have the SDDL form of the user's SID.
' Remove the user's RID ( the last sub authority)
' up to the "-"
'
DomainSID = mid(DomainSID,1,(InStrREV(DomainSID,"-")))
'
' Bind to the user object to retrieve the PrimaryGroupID.
' Build the SID of the Primary group
' from the domainSID and the Primary Group RID in
' the PrimaryGroupID.
'
set obj = GetObject(userADsPath)
lngGroupID = obj.Get("primaryGroupID")
strGroupRID = StrRID( lngGroupID )
DomainSID = DomainSID & strGroupRID
'
' Use ADsSID to retrieve a WinNT path or 
' a SID Bind string to locate the LDAP path
'
ADsSID.SetAs ADS_SID_SDDL, CStr(DomainSID)
if( ADS_SID_Constant = ADS_SID_ACTIVE_DIRECTORY_PATH ) then
   '
   ' With the LDAP provider, build a SID bind string and
   ' retrieve the Group object via this bind string
   '
   SIDBindStr = ADsSID.GetAs(ADS_SID_HEXSTRING)
   SIDBindStr = "LDAP://<SID=" & SIDBindStr & ">"
   set oGrp = GetObject(SIDBindStr)
   strPrimaryGroupADsPath = oGrp.Get("DistinguishedName")
   set oGrp = Nothing
else
   '
   ' Its a WinNT path, retrieve the ADsPath for the WinNT object
   '
   strPrimaryGroupADsPath = ADsSID.GetAs( ADS_SID_Constant )
end if
WScript.Echo "Primary group ADS Path for user : " & userADsPath
WScript.Echo "Is: " & strPrimaryGroupADsPath
WScript.Echo "Finished: " & Now