How to have an updated list of employee in a dropdown list



We want to record our annual performance evaluation in Smartsheet, we have a sheet with the list of employee and details.

I want to create a "Performance Evaluation" form when I can choose an employee name, my issue is that I don't want to update my dropdown list , only the list of employee from wich the dropdown list should be "feeded".

If anyone have a solution this will be great. Thank you in advance.