Can you post your API code? Maybe it can be modified to grab the port  name
also, to be stored  for later when you need it.

I think Stan Getz’ Access Cookbook book is well known to have a really good
section on changing the printers  from inside Access, most of which should be
transferable to Excel.

This web site:

safari.phptr.com/.../accesscook-CHP-5-SECT-4

has a lot of info  on the subject, however, it seems to be a reference to
other sources only, some of which are fee-based. It might be a jackpot, or
it might not be. For what it’s worth.