Your data is in fixed-width fields. The third column always starts at the same character position one line after another. substr would work just fine for this. Given the example data you posted, you just need to start at the 15th position, and read two characters. In other words, my $third_col = substr $line, 15, 2;

In fact, it's possible that you could just start at the 16th position and read a single character, but I would need to know more about the input data before I could be sure.

Anyway, for the data you posted, this works fine:

use v5.14;

say unpack( 'x15A2' ) =~ s/^\s+|\s+$//gr while <DATA>;

__DATA__
      1234 2321 0      45    1st
      2122 sdsa 0   0  34    
      2313 dsad        43    2nd    
      1232 ffff 0   0        1st 
      3213 sadf     0  34    
      2133 dada 0            2nd
[download]

I used unpack instead of substr, but either one would work fine.