Script: Add Computer to Workgroup or Domain

Const JOIN_DOMAIN             = 1
Const ACCT_CREATE             = 2
Const ACCT_DELETE             = 4
Const WIN9X_UPGRADE           = 16
Const DOMAIN_JOIN_IF_JOINED   = 32
Const JOIN_UNSECURE           = 64
Const MACHINE_PASSWORD_PASSED = 128
Const DEFERRED_SPN_SET        = 256
Const INSTALL_INVOCATION      = 262144

strDomain   = "FABRIKAM"
strPassword = "ls4k5ywA"
strUser     = "shenalan"
Set objNetwork = CreateObject("WScript.Network")
strComputer = objNetwork.ComputerName

Set objComputer = _
GetObject("winmgmts:{impersonationLevel=Impersonate}!\\\\" & _
strComputer & "\\root\\cimv2:Win32_ComputerSystem.Name='" _
& strComputer & "'")
ReturnValue = objComputer.JoinDomainOrWorkGroup(strDomain, _
strPassword, _
strDomain & "\\" & strUser, _
NULL, _
JOIN_DOMAIN + ACCT_CREATE)

Bron: http://msdn.microsoft.com/