GroupName = "test-group"

Const ADS_SCOPE_SUBTREE = 5
Set objConnection = CreateObject("ADODB.Connection") 
Set objCommand =   CreateObject("ADODB.Command") 
objConnection.Provider = "ADsDSOObject" 
objConnection.Open "Active Directory Provider" 
Set objCommand.ActiveConnection = objConnection 
objCommand.Properties("Page Size") = 10000 
objCommand.Properties("Searchscope") = ADS_SCOPE_SUBTREE  
objCommand.CommandText = _ 
"SELECT ADsPath FROM 'LDAP://dc=fabrikam,dc=com' WHERE objectCategory='group' AND name='"& GroupName &"'"
Set objRecordSet = objCommand.Execute 
Set objGroup = GetObject(objRecordSet.Fields("ADsPath").Value)

Const ADS_NAME_INITTYPE_GC = 3
Const ADS_NAME_TYPE_NT4 = 3
Const ADS_NAME_TYPE_1779 = 1
Const ADS_PROPERTY_APPEND = 3


strName = "Fabrikam\test-user"

Set objTrans = CreateObject("NameTranslate")
  objTrans.Init ADS_NAME_INITTYPE_GC, ""
  objTrans.Set ADS_NAME_TYPE_NT4, strName
  strUserDN = objTrans.Get(ADS_NAME_TYPE_1779)
  strUserDN = Replace(strUserDN, "/", "\/")

objGroup.PutEx ADS_PROPERTY_APPEND, _ 
    "member", Array(strUserDN)
objGroup.SetInfo