You might want to re-read your Mitsu manual
Are you quite sure those audio inputs on the TV aren't red and white? IF so, then you're looking at analog audio inputs.
Unless I'm mistaken, I've never seen a TV with a built in DD/DTS decoder, which is the only reason for digital interconnects to exist. FWIW, I believe the standard color for digital coaxial I/O is orange.
I HAVE seen plenty of receivers with DD/DTS decoders and these are where those digital interconnects are needed.
But, to answer your question, there are adapters available that will do what you need. These are available from partsexpress and, I believe, Radio Shack.