RF controller - third party compability

I understand that the Contour 2 remote controllers utilize both IR and RF signals, which works with both the Contour box (RF) and my stereo receiver (IR).

The issue is that my stereo receiver is located in a cabinet and the IR signal requires the cabinet door to be open in order to control the volume.  I've considered used an RF converter on the stereo, but I need to know if Cox supports any third party converters so I can use the Cox remote and close the cabinet doors.

Thanks -