Scan Label

I wrote this code to write data in Barcode I want to read item then shift automatic and fill lot number   

/* Add the following to DFI

   M => mo_num

   Ml => mo_line_no

   P => item

   T => lot_number

   */

   l_2dcode :=

      'M'

     || p_mo_no

     || CHR (42)

     || 'Ml'

     || p_mo_line_no

     || CHR (42)

     || 'P'

     || p_item_no

     || CHR (42)

     || 'T'

     || p_lot_number;

   fnd_file.put_line (fnd_file.output, '^FT273,188^BQN,2,3');

   fnd_file.put_line (fnd_file.output, '^FH\^FDMA,' || l_2dcode || '^FS');