Neei and vga switcher or other solution d an all-in-one dv

I have a duel montor setup. One has only dvi and vga inputs (main screen)and the other has vga, svdieo, and A/v as inputs (secondary screen). Problem is my graphics card has vga and dvi so dvi has to go to the main screen and vga has to go to the 2nd screen. I need the cable box (DVI connection) to go into the main screen as well, so thats 2 dvi outputs that need to go into a screen with only one DVI input. I have the same problem with vga on the 2nd screen cause xbox and cpu have to both go inthe sinle vga input. All the splitters I find have one DVI output to 2 differnt inputs. I need the opposite , two outputs to one input Please help.