PC to Handheld Link?

I have spliced to gether an old USB cable and a Link cbale for Gameboy Color, and also a cable for advance all in one. So its like PC to GBC or GBA. But I was wondering if there is an emu that allows linking up a GBC ROM to a GBC with the same game cart? If there isnt, somebody oughtta make one.

oh. I have TGB dual though. and if anyone know's how to code emu's. Maybe you oughtta try that.