Trying to not assign customer models PNs automatically?

Hey,

We take in lots of different customer models that we are wanting to store in PDM (professional), but we also have Part Numbers being assigned serially for internal components. Once we take the STEP/Parasolid and get the parts/assemblies, I cannot figure out how to prevent customer models from getting internal PNs assigned automatically upon adding to the vault. Currently what I have is using Control Logic on the Data Card to hide/clear this variable once I mark the component as "customer owned". Unfortunately, this needs to be done on each part (sometimes 200+ per assembly) and isn't very efficient!

A few thoughts I have had for this:

  1. Generate logic for folder specific triggers: We will always be putting customer models in a "[customer name]\\Furnished CAD" folder. Possibly use this as a trigger to block the automatic generation of the next PN in line? Not sure how/where this can be done.
  2. Use Dispatch to do it, but it would have to be "Before Add", because otherwise the PNs are still generated and our internal PN sequence would still be off. 
  3. After the models are added to the vault and PNs assigned, use VBA or something similar to "manually" remove the PNs and reset the counter to the last available starting point for the serial number.

No idea if any of these are any good and all are way out of my depth of experience, any assistance is appreciated!

Thanks!