Automatic border formatting

In a sheet I have a range (say A1:T40) where I enter data. In some of that cells (not all) I put bottom borders. When I enter a value in a cell of first range (say A2) this value is put in a cell of the second range (say AA2). Simple, so far. But, how can I check if there is a bottom border in first cell and if so, the same border type automatically put in the target cell.
Thanks