maybe it would be good if you could explain a bit in more detail what you want to achieve prko ?
there are ways to combine two render files into one for example and switch between the two sections. if you want to have two audio processes running at the same time the way to go would be to combine them into one render file.
or is it a combo of c++ and puredata or supercollider and c++ or something?
what is your application/goal?