You you mean the revs the auto-clutch works at, or the biting point of a manual clutch? Auto-clutch doesn't have a biting point as such, cos it's automatic...
If you want to change the rpm's, then use your gearing. I've never found any car have too low power (or torque) to move away (apart from the UF1000, but maybe that's cos of the rice-pudding skin I was dragging).
If you want to change the biting point (and I think these needs to be done, but I don't have a third pedal so I don't know), then you first need a 3rd pedal.