I'm afraid I don't understand your response either. The OP's request didn't seem ambiguous to me. While some assembly language programs might be difficult or impossible to convert to C for reasons of efficiency and performance, not all assembly language programs would be impossible to convert to C. I do agree with Ian though that, depending on the assembly language program, it might be difficult to justify the time and effort required to convert any particular program to C.
Speaking of ambiguous (grin), are you located in Rochester, MI., Rochester, MN., Rochester, NY., etc.?
Regards...