use strict;
use warnings;
use 5.012;

my $string = '79899920179';
my @results;
my $number;

while ($string =~ /(\d)/g) {
    $number .= $1;
    next if $number < 32;

    push @results, $number;
    $number = "";
}

say for @results;


--output:--
79
89
99
201
79