Get center point on surface

In our app, we have a selection set containing a bunch ofsurfaces or faces. I want to take a face from this set and identifythe approximate center point (center of gravity for example) on thesurface/face. The point has to lie on the surface, not at the truecentroid.

Can anybody help me figure out how to do this with the API?

Thanks,

Derek
SolidworksApi macros