Private Sub Worksheet_Change(ByVal Target As Range)
   sub1_Change Target
   sub2_Change Target
End Sub


Private Sub sub1_Change(ByVal Target As Range)

Dim rngDV As Range
Dim oldVal As String
Dim newVal As String
Dim lCode As Long
Dim wsList As Worksheet
Dim rngList As Range
Dim rngListID As Range
If Target.Count  1 Then GoTo exitHandler

Set wsList = ActiveSheet
Set rngList = wsList.Range("external")
Set rngListID = wsList.Range("externalID")

On Error Resume Next
Set rngDV = Cells.SpecialCells(xlCellTypeAllValidation)
On Error GoTo exitHandler

If rngDV Is Nothing Then GoTo exitHandler

If Intersect(Target, rngDV) Is Nothing Then
   'do nothing
Else
  Application.EnableEvents = False
  newVal = Target.Value
  Application.Undo
  oldVal = Target.Value
  Target.Value = newVal
  If Target.Column = 8 Then
    If oldVal = "" Then
      'do nothing
         lCode = rngListID.Range("A1") _
            .Offset(Application. _
                WorksheetFunction _
                .Match(Target.Value, _
                rngList, 0) - 1, 0)
         Target.Offset(0, 1).Value = lCode
   
   Else
      If newVal = "" Then
        'do nothing
         Target.Offset(0, 1).ClearContents
      Else
         lCode = rngListID.Range("A1") _
            .Offset(Application. _
                WorksheetFunction _
                .Match(Target.Value, _
                rngList, 0) - 1, 0)
         Target.Value = oldVal _
           & ", " & newVal
         Target.Offset(0, 1).Value = Target.Offset(0, 1).Value _
           & ", " & lCode
      End If
    End If
  End If
End If

exitHandler:
  Application.EnableEvents = True
End Sub

Private Sub sub2_Change(ByVal Target As Range)

Dim rngDV As Range
Dim oldVal As String
Dim newVal As String
If Target.Count  1 Then GoTo exitHandler

On Error Resume Next
Set rngDV = Cells.SpecialCells(xlCellTypeAllValidation)
On Error GoTo exitHandler

If rngDV Is Nothing Then GoTo exitHandler

If Intersect(Target, rngDV) Is Nothing Then
   'do nothing
Else
  Application.EnableEvents = False
  newVal = Target.Value
  Application.Undo
  oldVal = Target.Value
  Target.Value = newVal
  If Target.Column = 11 Then
    If oldVal = "" Then
      'do nothing
      Else
      If newVal = "" Then
      'do nothing
      Else
      Target.Value = oldVal _
        & ", " & newVal
      End If
    End If
  End If
End If

exitHandler:
  Application.EnableEvents = True
End Sub]