Otherwise, you're talking about two incompatible systems (RF and IR) and there's not much you can do.

Though I'm a little surprised that no such translator exists in the home automation world (a box that will learn both RF codes and IR codes such that when you send the box IR code "A" it transmits RF code "B"). When I looked into it one of the issues mentioned that that sampling and regen of analog RF was harder to do. Also, if a lot of RF-controlled boxes are now coming with IR as well, then the market may be too small.