I do it the other way, I have my machining in the MPF file & call the sub program for the bar pulling. Then I just get the MPF file to loop however many times I need it to which is usually the number of components I can get out of a length of bar. This way you can edit the mpf as you'd normally do when running & only need to load the SPF(Unless you want to edit the lengths the bar puller is using etc)