|Then you are willing to accept a VBA solution?|
If so, it'll still be VLOOKUP, but it will be done in VBA.
Let's say the Data Validation drop down where the names will be chosen is in Schedule A!A1
Let's say the list of employee names is in Employee List!A1:A10 with the nicknames in Employee List!B1:B10.
Use this code in the VBA sheet module for Schedule A:
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$A$1" Then
Application.EnableEvents = False
MyNick = _
(Target, Sheets("Employee List").Range("A1:B10"), 2, False)
Target = MyNick
Application.EnableEvents = True
Click Here Before Posting Data or VBA Code ---> How To Post Data or Code.