Sorry, but that just isn't how these things work. What you'd need for the scenario you envisage is a macro that not only calls the data from Excel but also creates both the dropdown it's going to populate and the one the data gets output to. Sure, it's possible, but that's a lot of coding effort just to spare you writing a few details. If these are names & details you re-use frequently in the same document or otherwise on a regular basis, you'd do better to create a custom quick part for each one and recall each as & when you need them. See:
https://support.office.com/en-gb/art...-41c771847a7b?