Struggled a little, but then decided why not to try like with #s5_scrolltotop?
Tried to add #s5_footer_body_section at the end of URL and it was working!
So I created an external url menu item and added in link just plain
#s5_footer_body_section
It will probably work with other div's, just you have to check your div's nave with Firebug or something...
Nauris