With some 2D Compositing and Render Order trickery you could make this work. this is what I have accomplished in all it's glory. if that looks good enough - READ ON
1. Put my map in a precomp looking like this - white on transparent
2. In the master comp I add the CC Sphere and set it to Outside
Now I have this:
3. Add the stroke layer style (right click -> layer styles -> stroke) and set it to black. now I have this:
4. Duplicate the precomp and this time set the CC Sphere to "Inside" instead of "Outside" and make sure it's below the previous precomp. now I got this:
5. Create a white solid and add the cc sphere to it too, with the stroke layer style;
Now all I have to do is set the Y rotation key-frames to match on the inside and outside sphere, and get paid.
Thank you, this is exactly what I was looking for.
You're welcome. Glad it worked.