The IR codes are provided by the manufacturer.  If you can find a Comcast remote with a grey OK/Select button ((eBay will have some but a red OK/Select button won't work), then we can tell you how to enter 5 digit EFCs to custom program the remote for your 47.5.  Or buy a JP1 flash cable for $20, and upgrade any JP1 remote- for example the Comcast red OK/Select button remote.