What's your source for this info? IF it's two wires, it should be composite.
Do a search, I tried to hack my FX35 RGBs a couple of years ago with no success, but somebody did it on an G35 or G37 don't remember, and he did using a ScanDo to translate VGA to RGBs signals (Red, Green, Blue + Sync, four wires).
Have you check the service manual? That should be your first stop.