I don't have any experience of this box myself but I did find this thread
http://www.altepg.com/forum/viewtopic.php?f=8&t=905&p=8200I'm guessing from this the answer is it is possible, but it will be difficult. The code for a T5000 wasn't built in and the poster had to teach the tivo the new IR remote codes needed. This isn't something I have done myself so I'm afraid I'd be of no help if you need to do this.
The thread does date from 2011 so if you already have the T5000 it may be worth trying all the inbuilt codes under FREEVIEW just in case one of them works but my advice would be to source another STB such as a Sony VTX-D800U from ebay.