See the attached workbook. I have added a worksheet change event handler to set F16 when when D16 is changed:
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, [D16]) Is Nothing Then
If [D16] > 5 Then
[F16] = "ABCD"
Else
[F16] = ""
End If
End If
End Sub
Kevin