OpenGL display map, polygons intersection

We developed our project with VC++ 6 to display a metafile map(of Suez Canal) and real radar video(for ships) on this map, using all moving and zooming utilities.

Now, we want to advance our project by using OpenGL graphics utilities, Please Help us to do the following:
1- How can we display a map (enhanced metafile) using OpenGL as a background to our work?
2- We already draw the video ships as polygons , but how can we determine the intersection between 2 polygons to be drawn with different color .
3- How to use zoom utility on the map and the polygons on it together?