Dim objSWbemLocator
Dim objSWbemServices
Dim objSWbemContext
Dim objSWbemInst
Dim proparray1
Dim proparray2
Dim Sitecode
Dim inputArray1(2)
Dim inputArray2(2)
Dim i
Dim bounds
Sitecode = "YOURSITECODE"

'Add boundaries to this array as you need them.
inputArray1(0)="192.168.1.101"
inputArray2(0)="IP Subnet"

inputArray1(1)="TEST 1 SITE"
inputArray2(1)="Active Directory site"

Set objSWbemLocator =  CreateObject("WbemScripting.SWbemLocator")
Set objSWbemServices = objSWbemLocator.ConnectServer( , "root\sms\site_" & sitecode )

Set objSWbemContext=CreateObject("WbemScripting.SWbemNamedValueSet")
objSWbemContext.Add "SessionHandle", objSWbemServices.ExecMethod("SMS_SiteControlFile", "GetSessionHandle").SessionHandle
objSWbemServices.ExecMethod "SMS_SiteControlFile.Filetype=1,Sitecode='" & Sitecode & "'", "RefreshSCF", , , objSWbemContext
Set objSWbemInst = objSWbemServices.Get("SMS_SCI_SiteAssignment.Filetype=2,Itemtype='Site Assignment',Sitecode='" & Sitecode & "',ItemName='Site Assignment'", , objSWbemContext)

'Retrieve the boundary details.
proparray1 = objSWbemInst.AssignDetails
proparray2 = objSWbemInst.AssignTypes

if ubound(objSWbemInst.AssignDetails)=-1 then 'There are no boundaries so create an array.
bounds=0
redim proparray1(1)
redim proparray2(1)
Else
	bounds=ubound (objSWbemInst.AssignDetails)+1 'Increase array for new boundaries
	ReDim Preserve proparray1 (ubound (proparray1) + ubound (inputArray1))
	ReDim Preserve proparray2 (ubound (proparray2) + ubound (inputArray2))
End If

for i= 0 to ubound(inputArray1)-1 'Add boundaries
	proparray1(bounds+i)=inputArray1(i)
proparray2(bounds+i)=inputArray2(i)
Next 

objSWbemInst.AssignDetails = proparray1
objSWbemInst.AssignTypes = proparray2
objSWbemInst.Put_ , objSWbemContext

objSWbemServices.ExecMethod "SMS_SiteControlFile.Filetype=0,Sitecode=""" & Sitecode & """", "Commit", , , objSWbemContext
objSWbemServices.Get("SMS_SiteControlFile").ReleaseSessionHandle objSWbemContext.Item("SessionHandle").Value