Combine fields for display?

Hi there – thanks for the great plugin!

I am trying to display a field with [pdb_list] that would be a combination of two other fields used in [pdf_signup]. For instance, in my sign-up form I ask for a First Name and Last Name separately, but then on the display side I would like to combine those two entries into a field called “Primary Contact”. I thought perhaps I could use a placeholder tag to do so? Is this possible?