standalone C++ preprocessor

Question

I'm looking for a standalone C++ preprocessor. I'll use with another language, so there's no point in running through a full fledged compiler, but it's a very limited script language, so the #define and #if and other directives will help me a lot.

For example, I'd be writing a file like this:

#define DEBUG
do some stuff
#ifdef DEBUG
    show a message box or whatever
#endif
do some more stuff

Answer 1

I found something which fits my needs, mcpp. It's a simple to use preprocessor and supports output to other languages thanks to a command line switch.