It would be better, quicker, and simpler to use a CAM program that can read DWG files, rather than try and use ACAD for something its not designed for. The only time I use acad for CNC is when I'm writing a prog 'by hand', and then I just use the ID command to check coords, clearences and so on. We use MasterCAM for the real machining work, (4/5 axis stuff, awkward shapes, and so on) and it's very good indeed. Post processors are fickle beasts to get working right at the best of times, even in purpose built programs. Basically, I wouldn't trust one written in LISP!