Voronoi on irregular and planar surface

Hey guys, 

Im trying to perform a voronoi diagram within voronoi cells, Ive uploaded an image so you can see what im trying to do. I know that i could ve used region intersection or other components to have the voronoi pattern solely on the surface, but when i do this the cells become polylines and i loose all the information relating to the cell (part that is crucial for my design).

Thanks a lot !

Marc