use HTML::Parser;

{
    package MyParser;
    use base 'HTML::Parser';
    sub start {
        my($self, $tagname, $attr, $attrseq, $origtext) = @_;
        if ( $tagname eq 'div' and $attr->{class} eq 'text12' ) {
            push @{$self->{text12}}, '';  # start a new text 12 collection
            $self->{in_text12} = 1;
        }
        else {
            $self->{text12}->[-1] .= $origtext if $self->{in_text12};
        }
    }
    sub end {
        my($self, $tagname, $origtext) = @_;
        $self->{in_text12} = 0 if $tagname = 'div';
        $self->{text12}->[-1] .= $origtext if $self->{in_text12};

    }
    sub text {
        my($self, $origtext, $is_cdata) = @_;
        $self->{text12}->[-1] .= $origtext if $self->{in_text12};
    }
}

my $p = MyParser->new;
$p->parse_file(*DATA);
print "Got: $_\n\n" for @{$p->{text12}};

__DATA__
<div class="text12">This text I don't need.</div>
<div class="text12">This long test that is at least 201 characters in length is what I want to parse.
<br><br>
Here is a list that I want to retrieve in this "div" tag.<br>
List:<br>
<li>item 1
<li>item 2
<li>item 4
</div>