so when I replied before i was just thinking of rigid joints. didn't really grok the question. sorry.
you could do this by configuring the "rest" position. it's not a particularly satisfying way because for some reason when you change configurations you have to drag a component a bit to get it to take effect. and revert position puts everything back to zero till you slightly drag something again. weird.
you can also drive all the joints you want to configure a bit, and do a "capture position" . when you configure the capture position there will be selections to configure each of the joint values that where changed by dragging them-

which may be a more intuitive way to set things.
attached are configured files for each approach.