Ok so here's my setup i have a view-sonic projector and a Sony bdv-e580 sound system i'm also trying to put the comcast digital adapter in my room. However non of my boxes have a coaxial in on them only hdmi, dvi, and component and composite. So i need a way to be able to convert the coaxial to either of those connections. I need your answer to include if it is possible and if it is a link to where i can buy the product at (my other difficulty).
If by coaxial you mean RF (that would be channel 3 or 4 on your TV tuner) then just a different cable would be useless. If you have a VCR then you could connect it to that and take the video and audio from that.