RCA cable to a TV that has several inputs, but not RCA?
For now, you can plug the composite cable into the component input, plugging the yellow video cable into the green (Y/brightness) input and the audio in normally. This will work as you expect, except the video will be in black and white.

A better solution would be to just get the Apple Component output cable and use that. Unless it's a 4th gen iPod touch, you won't be able to get VGA out and no iPod released to date will output DVI or HDMI. (Though the 5th gen touch should output HDMI since the 2nd gen iPad does now, but that's speculation.)