Hi,
I don't have a lot of experience with Perl, but I have worked a lot with CSV files and I'm very good at programming PHP scripts.
So, I would be able to write a script in PHP that would do what you need (you can run it in windows under command line or on Linux), or I could write a Windows application in a very simple to understand programming language like Visual Basic 6, which would run in Windows or Linux (under Wine)
I'd prefer to receive a sample of your original CSV file and your output file, just to make sure I understand what you want to 100% and that's pretty much it.
If interested, please let me know, I'd be glad to help you out.