A quick search on google found this:
http://www.ipenabled.com/bluetooth-rs232-usb.html
I've never used it or seen it in person, but the specs on the web site seem to match what would be required to connect to the RC. You would need to supply 5VDC, which you could pull from an unused PWM port. The data sheet shows 30-50 mA current draw, so a PWM port would be able to handle it.