Decompile Our .EXE Application

I have a .exe file that reaches into a database folder on our internal network and extracts data from the .DAT files for another program that's run off-site. This program was written by an in-house programmer that worked within our company. We no longer have access to the source code and would like to have someone who can help rewrite this application. It runs on our office server, but on a local desktop it keeps for Visual Fox Pro 7 - We installed it and now it keeps displaying a Program Error: Variable FINDAPP is not found. I am attaching the file so you can open it up and learn more about it. I will only select the bidder who provides a detailed explanation about the purpose of the application. This will tell me what you've looked into it and under stand it's function and will verify you're the right person to chose. We look forward to working with the most capable bidder.