I'm not entirely certain of the situation, but I'll suggest Inline
anyway. With Inline, you can write subroutines in other languages (C, C++, Fortran, Pascal, and Python currently) and use them as normal Perl subroutines.
In this case, though, it sounds like you have a bit of compiled C that you wish to access through Perl. You might be able to write some kind of wrapper (possibly using Inline C), but I think that would be too much work. As such, Fastolfe's advice is probably more pertinent.