I have written exactly one program for a robot and that was in school, some old worn out Puma, so given that.
I would look at a high quality die grinder.
They have some that are intended for the kind of use I think you are looking at.
Probably start with one at the slower RPM end of their selection.
I would start programming it so the cut is a lot like how a human would use a die grinder with a carbide burr to cut AL, lots of light passes.
Basically high speed machining techniques.
"http://www.youtube.com/watch?v=LtE2J9MraXY"]YouTube - VIBRA-FREE High Speed Aluminum Machining