take a look at this answer
to a similar question which shows a template to create your custom feed and all you need to do is add query_posts(array('monthnum' => (int)date("m") ));
before the loop.
take a look at this answer
to a similar question which shows a template to create your custom feed and all you need to do is add query_posts(array('monthnum' => (int)date("m") ));
before the loop.