Depending on which HR20 you have, you might ALREADY have the RF remote. Look on the back of the remote or in the battery compantment for the FCC ID sticker. If that is there, you have the RF version. The RF signal has to be changed on the STB and then it will work. The IR will continue to work for all TV's and AVR and other devices that you program the remote to control, but won't ALSO do IR for the STB.

You can also get this remote from D* for 25$, and you can USUALLY get them to send you ONE for free, but ONE only.

Otherswise, I have also used the little RF remote extenders, that replace ONE of the batteries in the remote and then you put a receiver in your AV cabinet. these work fine as well, I have them in use all over the USA but the only downside is that the battery that they use (which is rechargeable) has to be swapped about every 20-30 days depeding on use.