The line:

Dim WithEvents MapApp As MapPoint.Application

is the key to receive events from object in VB, i.e. without it you will not receive events. This line requires you to set reference to the MapPoint library. In VB6, Choose Project|References... and look in the list for MapPoint library.

When the line succeeds, in left combobox of Code window you will see MapPoint object. When select it, in right combobox you will see all its events.

When you complete these steps in VB6 successfully, I can try to help you in this also in VFP (since I have more experience in VB, here I can best resolve this type of errors).