What exactly is intended by the recursive reference:          $FirstItem[$FirstItem[$Index]] That seems kind of unusual.

As mentioned, unpack would do the job for you quite well, but even better would be to use a multi-dimensional array, or Array of Arrays (AoA), or even an Array of Hashes (AoH). AoH allows you to label the fields. AoA is probably more compact.

Consider:

      sub Read_File
      {
           while(<CLAIMS>)
           {
                 # (Choose one method only)

                 # 1: AoH method
                 my (%row);
                 @row{'a','b','c'} = unpack ("A8 A6 A2", $_);
                 push (@data, \%row);

                 # 2: AoA method
                 push (@data, [unpack ("A8 A6 A2", $_)]);
           }
      }
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So you can extract records like so:

      my ($record) = $data[$n];  # Index starts at 0, not 1

      # AoH
      print "$record->{a} | $record->{b} | $record->{c}\n";

      # AoA
      print "$record->[0] | $record->[1] | $record->[2]\n";
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