As far as I know, the IPRonto uses your home network to access the internet and the Extender. It does not do custom RF, just wireless b. The Extender receives the IPronto signals over your home wireless network, but just sends out the IR codes it is told too. There is no "RF" in the control sense, just access to a wireless network to access information and transmit signals to another philips device. Double check the philips archives on the pronto page and pull up the documentation to double check. Unless someone else says otherwise, I do not believe there is anyway to RF with this remote. Does the dish receiver accept any IR codes? The Extender can be put anywhere in network range to send IR codes. You can extend it even further if you have the 4 plug in IR extenders.
Just to be clear, there is an Extender for the IPronto and a RF Extender for other remotes. On the web site it says both are for receiving RF signals from the remote (or wireless network) and then transmitting the IR code. Go to-[Link: pronto.philips.com]