Allow Select all that Apply in Excel in Multiple Columns on the same sheet

Question

I am creating an activity tracker in Excel. I'd like to be able to "Select all that apply" from drop down lists in two separate columns on the same sheet.

I am using this VBA code for one column:

Private Sub Worksheet_Change(ByVal Target As Range)

'Code by Sumit Bansal from https://trumpexcel.com
' To make mutliple selections in a Drop Down List in Excel

Dim Oldvalue As String
Dim Newvalue As String

On Error GoTo Exitsub
If Target.Column = 6 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
            Target.Value = Oldvalue & ", " & Newvalue
        End If
    End If
End If
Application.EnableEvents = True
Exitsub:
Application.EnableEvents = True
End Sub

I found this code online, and altered it to apply to all of Column 6 instead of one cell.

I would like this to work for three columns on the sheet, Columns 1, 6, and 9. I imagine this is achieved by adding an Else statement somewhere below my If Target.Column = 6 statement.

Answer 1

Trying to answer your question, you may change the folowing If statement:

If Target.Column = 6 Then

into

If Target.Column = 1 Or Target.Column = 6 Or Target.Column = 9 Then