[Freesurfer] tkmedit scripting question

Aloha fellow surfers,

I am trying to script a few steps of my freesurfer pipeline. At the moment I am facing the problem that all my brainmasks need some manual intervention. Following advice from the wiki I try to set up tkmedit to clone from the aux to the main volume on the pressing button 3. Now my question how do I configure Button 3 from a tcl script so that my users do not have to do this manually every time? I would expect something like SetBrushInfo that takes more arguments than just brush, low, high, new, but my tcl-foo is very weak. If someone has a pointer how to set Button 3 to clone from aux vol I would be happy to hear it. Thanks in advance.

Best Sebastian