Multi-select dropdown list in Excel - how to extend VB script to work on additional columns?

Experts,

I'm NOT a VB developer and am trying to extend a code snippet I found online. The following code allows me to convert a standard dropdown menu into one that allows multiple selections. As each additional selection is made using the dropdown menu, the script appends each value separated by a comma.

The code works for column 5 of my spreadsheet and its dropdowns. However, I can't figure out how to alter the code to work for another column - say column 7 - that has dropdowns as well?

I tried copying and pasting the entire piece of code and simply updating the "Worksheet_Change()" class name and changing the reference to column 5 to column 7 but that didn't work.

Any suggestions?

Private Sub Worksheet_Change(ByVal Target As Range)
'Code by Sumit Bansal from https://trumpexcel.com
' To allow multiple selections in a Drop Down List in Excel (without repetition)
Dim Oldvalue As String
Dim Newvalue As String
Application.EnableEvents = True
On Error GoTo Exitsub
If Target.Column = 5 Then
  If Target.SpecialCells(xlCellTypeAllValidation) Is Nothing Then
    GoTo Exitsub
  Else: If Target.Value = "" Then GoTo Exitsub Else
    Application.EnableEvents = False
    Newvalue = Target.Value
    Application.Undo
    Oldvalue = Target.Value
      If Oldvalue = "" Then
        Target.Value = Newvalue
      Else
        If InStr(1, Oldvalue, Newvalue) = 0 Then
            Target.Value = Oldvalue & ", " & Newvalue
      Else:
        Target.Value = Oldvalue
      End If
    End If
  End If
End If
Application.EnableEvents = True
Exitsub:
Application.EnableEvents = True
End Sub