The folder for new favorites is any folder you set up within the favorites folder and point to with the item in preferences. That folder will appear as a sub folder when you view favorites. The default is to have new favorites appear in the favorites folder itself. If you use the new favorites folder, any new favorites will appear there.
There are extensions which can provide more functions for favorites. They can be found here:
http://kmext.sourceforge.net/ext4.htm
Look for "FavRenAdd Combo" and "FavAdd Plus NT | FavAdd Plus 9x".