TV out to VGA in

Not really sure if this goes here but since it mainly concerns watching movies, here it goes.
So heres my problem, I've got my xbox 360 and television/cable box hooked up to my tv. That works fine but what I want to do its somehow run a cable from the tv to my computer monitor which is located in a different area.
Essentially I'd be using my monitor as another television. But the cords Im looking at, all of them so far say vga in, meaning that it takes the image on the computer screen, and puts it on another screen.
I want the opposite of this. The best way would be going straight from my tv to my monitor, which has vga support. Yet, another problem is that my tv supports vga in only. Meaning that it takes whatever is on my computer screen and puts it on the tv.
Again, I want the opposite of this. I need to take whats on my tv and put it on my computer screen.
Another way I can think of doing this, it to go straight from the xbox and televison/cable box into the computer monitor. For this, I could leave my xbox and cable box hooked into my computer. Then with my xbox, I'd go from HDMI in to VGA out. From my cable box I'd go RCA in to VGA out.
Then I'd hook up a VGA splitter to my monitor and install the VGA output cords of both my xbox and my cable box.
This way, I would be able to watch cable/play xbox on my regular tv as well as my computer monitor without changing cords around.
This essentially would work, however, I cant seem to find a RCA in to VGA out cord. I also tried looking for S VIDEO cords with the same VGA output support, however, all of them so far is VGA in to (whatever) output. Again here I am, needing the exact opposite.
I need RCA (or S VIDEO) in to VGA out.

I know this is a lot to read, so I highlighted the main parts for you guys to get a fast understanding of what my problem is and what I need help with.
Any input on the subject is much appreciated.

Also on another note, neither my television, nor my monitor supports HDMI so yea, theres that.
Thanks ahead of time.