sells an IR to RF module that attaches to your Palm/Handspring/remote and transmits to a base station which, in turn, sends the IR signals to your components. I have one and it works well.
Yes, I have the up/down scroll buttons set to control the master volume on my reciever. Another of the hard buttons is mute. You can map all of them to any button that you can program.
You get used to it, kinda. That's one of the major things that I think the Pronto has a distinct advantage in. It's "set-up" like a remote control.
Hope this helps