VBA Code Not allowing multiple & repeating selection

[omfgvy]

Hi, so I am trying to find which item was purchase for each order. And so the drop down list in in column C and I am trying to allow multiple selections with repetitions. But once I put in the code, for some reason it would either NOT update or the code is not working. This is a code I found on YouTube. And I am just not understanding what was done wrong.

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 = 3 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

 

[Fluff]

Hi & welcome to MrExcel.
Which cells in col C contain the data validation?

 

[omfgvy]

Hi & welcome to MrExcel.
Which cells in col C contain the data validation?

It starts at cell C4 and all the way down

 

[Fluff]

All the way down to where?

 

[omfgvy]

All the way down to where?

So basically I am trying to make the drop down list all the way as I keep inputting information/data as time passes. But currently it is ending at C16 as of right now

 

[Fluff]

Ok, how about

Private Sub Worksheet_Change(ByVal Target As Range)

Dim Oldvalue As String
Dim Newvalue As String

On Error GoTo Exitsub
If Target.CountLarge > 1 Then Exit Sub
If Not Intersect(Target, Range("C4:C100")) Is Nothing Then
    If Target.Validation.Type Then
      If Target.Value = "" Then GoTo Exitsub
        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
Exitsub:
Application.EnableEvents = True
End Sub