That's a viable path...
-Set in Sheet2, in A1:Bxx the table Country / Currency
-Set in a cell, for example D2, a data validation based on a List; as the source of the list insert =Sheet2!$A$1:$A$xx
Now add a WorksheetChange macro:
-rightclick on the tab with the name of the sheet you are working on, select Display code; this will open the vba editor.
-copy the following code and paste into the rigth frame on the vba editor
VBA Code:
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$D$2" Then '<<<<
Application.EnableEvents = False
Target.Value = Application.VLookup(Target.Value, Sheets("Sheet2").Range("A1:B20"), 2, False)
Application.EnableEvents = True
End If
End Sub
Now when you select a Country from he data validation dropdown menu, the content of the cell will revert to its currency
If you wish to restrict the list as soon you start typing (thus not using the data validation menu) you will use a combobox to be populated dynamically on combobox change; or will use the standard combobox features.
Bye