Well, if your in direct sunlight, you may not have much luck with anything. But, for about 50 bucks or so you can try the pyramid thingys. I know Powermid X10 makes some, and also RCA. You would point your remote at the transmitter, be transformed into and RF signal, then picked up by the reciever near the radio and then either blasted to the radio from the base, or through an IR eye plugged into the back of the remote.

Usually they are called IR Extenders or something like that. Kinda unreliable, but work and are cheap.