Getting the zip code out from mappoint for any point

Hello,
I have seen in MapPoint are the ZIP codes defined as areas. This would allow me to get a ZIP code for any point in my map.

I have a list of 45000 locations in Austria ( defined with GPS coordinates ) and have to search the ZIP code for it.

How can I do this with MapPoint?

Thank you!!

Check out this article by Walt Cygan: Reverse Geocoding, Pt. III
http://www.mp2kmag.com/articles.asp?ArticleID=50