You make it sound like you're trying to mount your computer to the frame. Is that the case? Or did you mean that there's no room on the *base bar* that came with your P2C frame?
If the latter is what you meant, try purchasing a computer adapter that will attach to the aerobars, and allow you to mount your computer off of an aerobar. See how the computer is mounted in
this picture if you aren't sure what I'm talking about.