Excel and Removing Columns

I had a situation today where I had a spreadsheet that contained hundreds of columns. I only needed five or so of these and I didn’t fancy going through them one-by-one to delete the unnecessary ones. I found the below snipped of VBA on stackoverflow. The code ran almost instantaneously and deleted all columns that I didn’t need. The country names are the columns that I needed to keep. I didn’t change/need the part of the code that deletes cells if they don’t contain the string ‘homer’.

Sub deleteIrrelevantColumns()
    Dim currentColumn As Integer
    Dim columnHeading As String

    ActiveSheet.Columns("L").Delete

    For currentColumn = ActiveSheet.UsedRange.Columns.Count To 1 Step -1

        columnHeading = ActiveSheet.UsedRange.Cells(1, currentColumn).Value

        'CHECK WHETHER TO KEEP THE COLUMN
        Select Case columnHeading
            Case "England", "New Zealand", "India", "South Africa", "Malaysia", "China", "Philippines", "Scotland"
                'Do nothing
            Case Else
                'Delete if the cell doesn't contain "Homer"
                If Instr(1, _
                   ActiveSheet.UsedRange.Cells(1, currentColumn).Value, _
                   "Homer",vbBinaryCompare) = 0 Then
                    ActiveSheet.Columns(currentColumn).Delete

                End If
        End Select
    Next

End Sub