Send Attachment With Order Confirmation

I need to be able to send an attachment with an order confirmation email. I'm using Shop Script (a Smarty templated ecommerce software) and when we manually approve orders, I would like to be able to attach and send an attachment to the customer with the order completion email. There are different attachments needed for different customers. What needs to be done is an edit of the ss_mail function contained in /core_functions/[login to view URL]