Danke, hab es dann doch noch selbst hinbekommen mit VBScript
Function CreateMemberOfObject(strDomain, strUserName)
Dim objUser, objGroup
document.write("Benutzer: " & strDomain & "" & strUserName & "<br><br>")
Set CreateMemberOfObject = CreateObject("Scripting.Dictionary")
CreateMemberOfObject.CompareMode = vbTextCompare
Set objUser = GetObject("WinNT://" _
& strDomain & "/" _
& strUserName & ",user")
For Each objGroup In objUser.Groups
CreateMemberOfObject.Add objGroup.Name, "-"
document.write(objGroup.Name & "<br>")
Next
Set objUser = Nothing
End Function