I don't know of a DSS receiver that is only RF. All the units I know of are switchable between RF and IR. On my Sony SAT-A3, it's a configuration option on the setup menu. Pronto can learn the IR codes of a DSS receiver that is set up for IR control, but it cannot learn RF codes. Configure your DSS receiver for IR control and you'll be fine - works great for me.

If you need control of the DSS receiver in a remote room, I'd recommend the 'PowerMid' IR remote extenders, which are also OEM'd by RCA and Panasonic. You'll get control of everything remotely, not just the DSS receiver. Again, mine works well (I have the Panasonic branded version, since I prefered the 'cone' styling to the PowerMid's 'Pyramid' styling)