$whole_thing =~
      m|<some unique html start string>(.*?)<end string>|s;
    $good_chunk = $1;

##</code><code>##

<div id="good_chunk">

##</code><code>##

while ( my $token = $p->get_tag( "div" ) ) {
    if ( $token->[1]->{'id'} eq 'good_chunk' ){
        # get the entire contents of the div, as HTML,
        # for further parsing
    }
}