Steve,
It's easy, providing you've got the tools and the source code.
You need EVC++ from Microsoft, the HPC SDK, and patience
. Your biggest problem may be in finding the HPC 2.0 SDK, as the earliest one that I have is HPC 2.11 Pro...
Once you've got stuff installed, load the stuff into EVC++, select your processor from the dropdown list, and click "build".
You may have to create a configuration for the SH4 architecture, but this will just be a crib of another predefined config for the project.
One slight issue you may have is that EVC++ 3.0 uses a slightly different project format to EVC 2.0, which I think is what was originally used to build CE2.0... But that again is just a question of fiddling
Good luck. If you want a hand, drop me a mail - or post here and we'll enlighten the world
Cheers,
Nick.