my $htm = HTML::TokeParser->new( \$your_html_page );

while ( my $tkn = $htm->get_token ) {
    if ( $$tkn[0] eq 'S' and $$tkn[1] eq 'a' and $$tkn[2]{onclick} =~ /^javascript/ ) {
        my ( $url ) = ( $$tkn[2]{onclick} =~ /\("(http:.*?)"\)/ );
        $url =~ s/\\u([0-9a-f]{4})/chr(hex($1))/ge;
        # do something with $url;
    }
    else {
        # do other stuff with other parts of html data...
    }
}