Perl Decompile

[solitary]

I've been using perl for the last five years and this will be the first time I've had to ask for help. Credit to the creators becuase this language is very simple to start, but very powerful once you get on a roll. However, I have a big problem. One of the companies we rely on to get us information from a purchased advertising system (Idiots, Inc) wrote an export program to collect ad information so that we can import it to the web. We prefer to do this directly, but security concerns killed that. The files are then FTP'd to our server where we parse them. Over time this has required a few tweaks. One is that when the first of the month falls on a weds or thurs it interfered with one of our classified publication exports. Their solution? Build tables for the next three years so the system knows which days will get bungled and have a work around. The problem has become they used a compiled perl script, and they lost the source. This makes things really bad, becuase our timetables for minor changes are now months away. I really began to doubt their abilities when they said they compiled it so it would run faster. I have the .exe but can't seem to do much with it, as I'm not sure how to decompile or de-encode it. Any help would be happily accepted.