I know that @NeilFerreri has developed some macros to use with the bit setter. You might want to take a look at this thread.
Post 5 in that thread has links to get the macros and in post 42 he said to set the position of the bit setter with:
%global.state.PROBE_X_LOCATION
&
%global.state.PROBE_Y_LOCATION
I hope that gets you started on the right track. Bear in mind I have zero experience with the bit setter, I just have read a lot on here and remember some of it.