Be careful of some of the replies here, I think they are misunderstanding your question. It sounds like you want to collect user information from a web form, then post the required info to Bank of America for credit card processing, so you don't want to submit the user's form directly, you want to build up a list of key/value pairs and POST that to BofA.

A search on CPAN revealed Business::OnlinePayment::BankOfAmerica. I haven't used that but I have used Business::OnlinePayment::AuthorizeNet and it's all pretty straightforward. If anything, you can view their source to see how they're posting it.