magento xml feed

Hi, i need an product xml feed for magento. The xml feed can be based on tis extantion : [login to view URL] I need the extantion to be modified so that instead of all the products appearing on one page ([login to view URL]) they will be grouped into the store categories in a tree menu so that once you click on a category in the menu you get the xml feed for all the items in that category. Thanks