Convert mid-tolerances to STEP without changing original part file

Hello,

For our company we want a VBA/Macro code to minimalize the work for the CNC-programmers. 

What we want it to do:

Set mid-tolerances  and save this as a step.

 I already have combined some code. This code sets the tolerances to the middle and save this as a step.So far, so good.

The only problem is that is changes the orginal part file to mid-tolerances (We can choose to not save it, but I don't like that idea)

I only want the step file with the mid-tolerances and the part file with the normal tolerances. We want it this way, so that we don't mess with the mates in the assembly's and the CNC-programmers don't have to offset things. 

I think it must make some kind of copy.

Is this possible? and how? 

It's the firt time I work with VBA/macro (:

SolidworksApi/macros