Point In Polygon With TSQL

I've got a table with lat/longs for specific points:

CREATE TABLE [Point] (
[PointID] [int],
[Lat] [numeric](10, 6),
[Lon] [numeric](10, 6)
)


I have another table with polygon borders as lat/longs:

CREATE TABLE [Polygon] (
[PolygonID] [int],
[PointNum] [int],
[Lat] [numeric](10, 6),
[Lon] [numeric](10, 6)
)


What I need to do, is come up with a script that will determine which Polygon contains each point. I'd like to be able to assign a PolygonID to each record in the Point table, or give it a 0 if there is no polygon that contains that point.

I'm looking for a way to do this within SQL Server (or possibly with the use of an extended stored procedure if necessary).

Thanks for your help and suggestions!

Tyler