Best sellers "page"

[barricades]

Hi, thanks for what looks to be a cracking mod. Just what the doctor ordered. But I wonder if anyone who is a bit more technically minded than me can tell me in what file do i need to place the - <?php echo zen_href_link(FILENAME_BEST_SELLERS); ?> - so that the link for the page appears at the bottom of my categories sidebox under the rest of the categories?

Thanks for any help

dave