yep mudrat is spot on. There is a little switch which the lever hits when you select low range - lights up an organge box saying 'lo' in the car indicator display thing...
I have the exact switch hanging off my old gearbox gearstick linkages. But you'd have to have the wiring + connector hidden under the carpet to connect up the switch (wiring should come from around drivers footwell, up the side of the centre console, then accross the back to where those 2 studs are. i think from memory the connector is blue and rectangularish.
Hope that helps
Cheers
-Adam