I did a lot of google searching and asking and finally found an answer.
It , turned out, as simple as this:
Copy D4 and paste special(Link) to say 100 cells(not only E4 and C3, all these cells now acquire color of D4 which is conditionally formatted wrt value in A1.
The utility of this tweak is, making excel cells very small in length and breadth, we can create map of world where contours of countries looks fairly good. A1 represent data area. D4 is a seed cell to color a country. There will be 200 seed cells for 200 countries. But, the map itself occupies millions of cells. Heat Maps can be produced with some toil.