From an engineering perspective, I would be surprised if you could do this simply.
The PCI spec cites an electrically balanced circuit - remember the signals going down these tracks are just bustin to 'jump' out and interfere with anything they can. Without designing a balanced microstripline circuit, you would screw up all the characteristic impedences of the interface.
So I would say, can be done at home - requires expensive CAD/simulation software to design a PCB bridge circuit.
JMHO, Vin
