How can I connect a Sirius receiver to a radio with a single-AUX input?

I have recently obtained a second SIRIUS receiver which I'd like to connect to my Cambridge Soundworks table radio. The Sirius output is via an RCA cable; the radio has only a single AUX input jack. I'd prefer not to use FM transmission to hook the thing up. Is there an adapter that will allow me to do this? Thanks in advance.