Video out over Coax ?

[Structural Integrity]

In my computer I have a GeForce2 (7400 TI from the very top of my head (64 mb)) with a TV out. Now, I've never used this TV out because I couldn't be arsed to find out how to use it.

But, since my mom and dad have been bugging me lately of finding out how to connect it to a TV, so they can watch all those "kewl" movies I have on CD, I have to find a way of doing this.

I'm not VERY interrested in dragging my computer downstairs and working my way through all those cables behind the VCR just to have my parents watch a single movie, thus I need a more practical solution.
What I was thinking is connecting the card to a coax cable (the ones used for TV signal transmission) and giving the other TV's the oportunity to catch the signal. We have these cables throughout the entire house (having 4 rooms with TV's) and making an extra connection is not that much work.

Does anyone happen to know how to get this done?