my $string = "The quick brown fox jumps over the lazy dog.";
my $count = 0;
$count++ while $string =~ /(the)/gi;

##</code><code>##

while (<IN_FILE>) {
  my $count = 0;
  MATCH: while (/(\Q$some_string\E)/gi) {
    $count++;
    if ( 2 == $count ) {
      # do something
      last MATCH;
    }
  }
}