I'm lost at this point. If 'rdes' is a C program (which I'm assuming you mean it was a program written in C and then compiled to a binary executable for your system), then I don't know what else you could try. I'm a bit confused about your message to me privately, though, where you said you added the shebang line with no effect. If this is a binary executable, a "shebang" line is not desired, and would have corrupted the executable (assuming your editor let you edit it at all). Since you reported no change in your findings, something is not as you say.

Regardless, I don't think this is a Perl problem. Contact your system administrator and/or the vendor for this 'rdes' program.