Gary,
I have been working on a program to convert Gerbers to gcode. So far
it is not completely working. It should output a good gcode file for
drilling the vias as long as you have drill bits for all the via sizes
that you used on the PCB. Parsing out the trace edges is still a work
in progress. I am trying to clean up the code some and support rectangular pads right now. It might work ok for a very simple PCB, but most likely you would have to do a lot of editing by hand to fix the problems.
http://sourceforge.net/projects/gerbertogcode/
I am also using EMC for my gcode testing.
Matthew