"compile from a 32-bit system for a 64-bit system" - I don't believe so. I'm pretty sure you need 64 bit OS (e.g. Windows 7-64) to install 64 bit MATLAB and use the 64 bit compiler to create a 64 bit application for running on a 64 bit OS. You can't do it from a 32 bit OS.
However, you can install either and/or both 32 bit and 64 bit MATLABs on your 64 bit system, and use the 32 bit MATLAB to compile for 32 bit systems, and the 64 bit MATLAB to compile for 64 bit systems.