Hope someone can help!

I have just bought a Dell XPS420 with the Windows Media Centre software on it, along with a digital TV board etc. I want to connect this directly to the TV for watching DVDs, internet use etc, however the TV only has an S-video link / Scart / red, yellow & white jack plugs etc, and doesn't have DVI. It's a really good (Sony) TV, so I don't really want to change this. How can I get it working (including sound, as the TV has a good cinema surround system as well)?

I was hoping that there was something that went from DVI to Scart, which would send sound signal and picture to TV? All I need to do then is switch it the the relevant AVI set-up when I want to view the computer?

Is this possible ?