Merging 2 VBA Codes

Hi Guys,

I'm new to VBA coding, so please bare with me

I want to implement multiple selections within several drop down list, after googling and searching here and there i managed to find the following coding lines which work great in any given column:

Private Sub Worksheet_Change(ByVal Target As Range)
Dim rngDV As Range
Dim oldVal As String
Dim newVal As String
Dim lUsed As Long
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 = 9 Then
    If oldVal = "" Then
      'do nothing
      Else
      If newVal = "" Then
      'do nothing
      Else
        lUsed = InStr(1, oldVal, newVal)
        If lUsed > 0 Then
            If Right(oldVal, Len(newVal)) = newVal Then
                Target.Value = Left(oldVal, Len(oldVal) - Len(newVal) - 2)
            Else
                Target.Value = Replace(oldVal, newVal & ", ", "")
            End If
        Else
            Target.Value = oldVal _
              & ", " & newVal
        End If
        
      End If
    End If
  End If
End If

exitHandler:
  Application.EnableEvents = True
End Sub

Now, The issue is that I want the multiple selection to apply to at least 2 Columns, I've tried several combinations wit If/End if/Else & Else If, and after cleaning up I seem to disable the loop effect,

Can anyway help?

kindest regards!

Cruz