Apply a Macro to range of cells - excel

Question

I need to apply the code below to a range of cells (i.e. B24:B28) - how do I edit to make this happen?
Private Sub Worksheet_Change(ByVal Target As Range)
Dim Oldvalue As String
Dim Newvalue As String
On Error GoTo Exitsub
If Target.Address = "$B$24" 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

Answer 1

If Target.Address = "$B$24"
This is the line you're interested in modifying.
If you only want it to occur on a single cell, you likely want to add above it
If Target.CountLarge > 1 Then Exit Sub
Now that we know it was only a single cell that was clicked, we can use intersect to keep the code short and replace the first line with
If Not Intersect(Target, [B24:B28]) is Nothing Then
Alternatively, we could just replace the single line with
If Target.Address = "$B$24" Or Target.Address = "$B$25" Or Target.Address = "$B$26" Or Target.Address = "$B$27" Or Target.Address = "$B$28"
But as you can see, that gets a bit less elegant pretty quickly.
My advice - replace:
If Target.Address = "$B$24"
With:
If Target.CountLarge > 1 Then Exit Sub
If Not Intersect(Target, [B24:B28]) is Nothing Then
Final code becomes:
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, [B24:B28]) is Nothing 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
In the future, if you want to change the Range this affects, you can just modify the [B24:B28]