Z 0 Home set to a lower height?

Is there a way to set Z0 home at 50 mm lower than it is now. or should I just let the spindle stall home when it hits the Z stepper motor?. I want the spindle height to be at max but the carrier bracket could be quite a bit lower, to reduce the unsupported length of spindle. Could do it with a BB macro, but then have to remember to set it. Got the slider moved up this morning, struggle to get the last two screws out. The extra height will be nice, thanks for the heads up yesterday.