Hello friend, thanks for the tip. It has helped me .. but I own many other files as for example:
981139804_ABCDEF12345678765463565E_28062016172508.TXT
981139804_ABCDEF12345678765463565E_28062016192508.TXT
981139804_ABCDEF12345678765463565E_28062016112508.TXT
981139804_ABCDEF12345678765463565E_28062016102508.TXT
981139804_ABCDEF12345678765463565E_28062017102508.TXT
971305332_XXXXXX12345678765463565E_28062011102508.TXT
971305332_AAAAAAAA12345678765463565E_28062011102508.TXT
971305332_CCCC12345678765463565E_28062011102508.TXT
971305332_CCCC12345678765463565E_28062020102508.TXT
And when that occurs, it is only returned to a number, that is, I needed to return ordering the first column and the last.