one small pulley
one big pulley
You could break up the belt into many smaller sections and then join them together to make a chain. It would take long but I think it's the only way to do it. Here is a really good link that shows how to create a chain mechanism.
I also have it summarised in the word doc if you don't have time to go through all the videos
AttachmentsHow_to_-_Chain_Assembly.docx, 12.4 MB
To my knowledge, belt cannot be simulated in CATIA. Mostly in IDEAS it may work. Share if you crack it down.