zoom

Hi,
I am currently displaying a 3D surface…using MFC and OpenGL
Now I want to add a zoom feature to my application.
This is what I want to do…
Using mouse I will draw one rectangle(i.e select the region) on the surface,I want to zoom that particular region…
How should I do this…or what do i need ,in order to develop such kind of feature.

Thanks
aus

why don’t you move the camera to the selected region (also consider the depth,frustum, etc) ?