I probably missed something, but what is so special with this code and why aren´t we allowed to modify it?
To me it looks like some very basic shadowmapping with a dirty blur...

Do you know that the hard thing about shadowmapping is to get rid of aliasing?
Why do you call it dual pass?
Where does TargetMap come from and how do you handle its little precision?
What is meant to be stored in the projection textures alphachannel?