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?
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
you can do that with any computer to a USB DAC such as Benchmark, PS Audio or Bel Canto. A very easy way to do it is with a MacMini.
I already have a DAC with coax and toslink inputs. I am trying to avoid buying a new DAC.
I was not clear, I guess what I meant was it would prob be easier to get a new DAC. I believe any conversion process would prob degrade the signal quality.
Here is another vote for the HagUSB. I have compared with the M-Audio transit and some Generic PCI soundcard, and the HagUSB is my preferred route. You can find more favourable posts here on Audiogon, if you do a search.

Good luck,