I run a toe based QS-- it has buttons on the shifter - toe - thing. It has two wires that run from that to the PC3. Your shift rod based one is the same-- two wires that run to the PC3. Just tap into those using a relay. I have some schematics that i've posted before that show how to trigger a closed circuit when the shifter solenoid is hit.
basically its relay output -> shifter solenoid (it then y's to the 85 of another relay, that has 30 & 87 being your newly tapped "quick shifter leads")
that make sense?
Turbo Hayabusa / R1 / Ducati 848 / GTO / Audi A6