CNC Toolpath Transformation

I use two versions of the same program for creating tool paths for numerically controlled milling machines. I want to be able to convert tool paths created for one machine (A) to run on another machine (B). Instructions for (A) are all for moves in one quadrant and (B) for another. It is essentially a coordinate transformation, after allowing for a certain x,y offset. Specific embedded commands can be translated from one machine to another. They will always be consistent. (e.g. G0 on machine (A) would be G1 on machine (B). It would also be good as a fail-safe to specify a boundary to make sure that after our transformation we have not told the machine to travel to a place that would be unsafe. The files are in ASCII format. The program should be able to work on an individual file or a group of selected files. Example files are attached.