You create an IGatherNotify interface object by calling CreateObject, as in the following example, where objGatherNotify is the name you give to the IGatherNotify interface object:
Option Explicit
On Error Resume Next
const GTHR_CA_ADD = 0
const GTHR_CA_DELETE = 1
const GTHR_CA_MODIFY = 2
Dim objGatherNotify
Set objGatherNotify = CreateObject("GatherSvc.GatherNotify.1")
objGatherNotify.Init("NotificationTest")
objGatherNotify.OnDataChange GTHR_CA_ADD, "C:\UpdateList.htm"
objGatherNotify.OnDataChange GTHR_CA_DELETE, "C:\OldList.htm"
objGatherNotify.OnDataChange GTHR_CA_MODIFY, "C:\ChangeList.htm"
'Release GatherNotify object
Set objGatherNotify = Nothing