50564 oscommerce email mod

Hello, I need an add-on for my classic Oscommerce store.. I want to be able to send emails with attachements to my customers... (For example .pdf , .doc , .bmp, etc. etc.) The file that needs modification is ...../admin/[login to view URL] and maybe a modification on one of the functions/classes it uses. This is up to you. I do not own a test-server (only a live-store), so you'll have to do modify the files on your own server. please tell me how long it'll take.