Direct USB computer to coaxial outboard DAC


I am looking for a way to bypass a sonos or apple TV. I want to know if there is a cable that goes from computer usb to either a coaxial or toslink connection in outboard DAC? If not possible what would be a cheap alternative without sacrificing sound quality?
beerad
You need something like the HagUSB from Jim Hagerman or Blue Circle's "Thingy" (their name, not mine). I believe there is a thingy on Agon for sale now.
thanks for the response Nycwine! the HagUSB looks like a real cool product. I will let you know what happens.
No cables that will do it.
Here is a converter that will covert the signal.
Trends UD-10.1 USB Audio Converter

http://www.trendsaudio.com/EN/Index.htm