This is not just about changing a 32 to a 64 in the code (it maybe would be in a 100% perfectly organized code). A lot of stuff is related to this and would have to be revised, certainly causing tons of problems and bugs.
To clarify this once again: I won't apply any major changes to the current CS2D build because it's bad to invest so much in such an outdated and especially limited game engine. It's like trying to build a huge villa on a rotten foundation. Everything will explode sooner or later so it's basically wasted time to do it.