i found this on the internet (it doesnt do a precheck to see that the user isnt already a member of the group,,,which i presume will result in a runtime or at least speed issues..)
' GroupAddLots.vbs
' Free example VBScript to add users to a group.
' Author Guy Thomas
' Version 2.3 - May 2005
' ---------------------------------------------------------------'
Option Explicit
Dim objRootLDAP, objGroup, objUser, objOU
Dim strOU, strGroup, strDNSDomain
Dim intCounter
' Check these objects referenced by strOU, strGroup exist in strOU
strOU = "OU=Newport,"
strGroup = "CN=Coal Porters,"
' Bind to Active Directory and get LDAP name
Set objRootLDAP = GetObject("LDAP://RootDSE")
strDNSDomain = objRootLDAP.Get("DefaultNamingContext")
' Prepare the OU and the Group
Set objGroup = GetObject("LDAP://"& strGroup _
& strOU & strDNSDomain)
Set objOU =GetObject("LDAP://" & strOU & strDNSDomain)
' On Error Resume next
intCounter = 1
For Each objUser In objOU
If objUser.Class = lcase("User") then
objGroup.add(objUser.ADsPath)
intCounter = intcounter +1
End If
Next
WScript.Echo strGroup & " has " & intCounter & " new members"
Wscript.Quit
End of Add lots of members to group VBScript