RF for XFINITY large button remote?

Can the XFINITY large button remote be paired to work via RF instead of IR. I followed the usual instructions (press and hold SETUP key until it turn from red to green and then press the XFINITY key and follow on screen instructions) except no on screen instructions ever show. Any help would be appreciated. I am trying to set this up for a 99 year old disabled vet. He does not have the coordination to point to get IR to work, and he can't see the buttons on the regular remote.