Just a point from your first post, you can have many last rows eg:

Sub test()
    Dim lr As Long, lr1 As Long, lr2 As Long 'etc...
    lr = Cells(Rows.Count, 1).End(xlUp).Row ' last row of column 1 ("A")
    lr1 = Cells(Rows.Count, 3).End(xlUp).Row ' last row of column 3 ("C")
    lr2 = Cells(Rows.Count, "AB").End(xlUp).Row ' last row of column 28 ("AB")
    ' etc...
End Sub