What you need to do is to create a form with the combo box on it that selects the name, then either use a button on the form to run the query, or trigger the query from the combo box's after update event. I don't think you can use a combo box from a query parameter prompt. But it won't make any difference to the user anyway.
Just have the button that launches the query launch the form with the combo box instead. Then replace the criteria in the query with [Forms]![frmNewForm].[cboYourComboBox]