You would do something like

PHP Code: 
$html get_html('http://site.com/topic.asp?id=2'); //Not sure about the function.

foreach($html->find('table tr') as $tableRow)
{
    
//You can now use this like the DOM
    
$topicLink $tableRow->find('td font.new-row a')->val();

This is not regex but Dom traversing, such as jQuery inside PHP.