How do you embed addtional RSS feeds into the  section of your theme
You can use drupal_add_feed() or if you don't want to have an icon appear
on the page itself

 drupal_add_html_head_link(array(
    'rel' =&gt; 'alternate',
    'type' =&gt; 'application/rss+xml',
    'title' =&gt; $title,
    'href' =&gt; $url
  ));