Hi there!
Let me welcome you to EA, first off. You won't be disappointed, in fact in a few weeks I predict you'll go running to your boss going hey look at what we can get for the cost of one engineering hour.
Secondly, I'm not sure what it is you are trying to achieve here. I thought I did, but then you got to that preprocessor macro and I kinda went huh?
It looks as if you're after changing the reverse-engineering behaviour by changing the code generation templates. If so, that won't work.
The EA code generation templates are forward only. You cannot script the reverse-engineering process (not that I haven't asked for it, but it didn't get a heap of votes). You could write your own using EA's API, but I wouldn't recommend that if all you've got is a month.
Basically, if what you want is a reverse-engineered UML model of some truckload of C++ code, and that code has preprocessor macros which affect the structure of the code (as in class generation rather than "#define PI 3.13" or "#define MAX(x, y) (x>y)"), then the simple way to get where you want is to run the code through the preprocessor before you import it into EA.
Hope this helps. If not, please don't hesitate to say so. We really are here to help.
Cheers,
/Uffe