Do you know about how to form ISO8583 messages? Do you have a sample formats that you can show me? Is there a perl module that handles this?

To the best of my knowledge there isn't a Perl module that deals with ISO 8583 messages (for those who don't know ISO 8583 is a standard for message passing in financial systems).

If you're interested in writing one I'd suggest purchasing the standard from ISO, since that's the only way you'll get all the info you need.

It will probably be worth your while looking at jPOS, a Java based financial transaction framework. It handles ISO 8583. It might be the simplest option to use it via Inline::Java.