In VEGAS speak the external monitor is connected via some digital to analog device from a firewire card. Many digital cameras have the necessary pass through, so do free standing DVA convertors. That's the way to go.

To get a signal to from a video card (not recommended) to a TV it depends on the break out box or video card. Basically all that's necessary is either a "S" video or standard RCA plugs.

Time to dig out the manual to see how your particular model gets set up. Most require some kind of switching from Window's control panel or some control the device itself provides and then you basically are only going to get a screen capture of whatever device can play a video. You won't see the 'real time' playback you see talked about in the forum all the time.. So you'd need to play the video in something like Microsoft's Media player, that gets captured and is seen on your TV. The quality usually isn't good.