What kind of parts are we talking about? Ones that require 2D or 2 1/2D programming? Or are they parts that require 3D programming? Were the parts drawn in Surfcam or a solid modeler like Solidworks etc.? If your engineers have models of your parts, it might be better to just re-cam them. If they were drawn in Surfcam with 3d wire and surfacing, ouch. That is tedium compared to a parametric solid modeler. Let us know a little more about the task, and perhaps we can help.