Add customizable button to catalogue

Customer would like to have a customizable button in the catalogue. They have many bill requests from people who attend their trainings. They request this via email and there is too much communication between them. To make this easier they want to embed a button in the catalogue to each training named "Request bill". So the attendees can click on this button that has a link embedded.  This takes them to an outlook form to fill in their details so the bill can be sent to their email address.