Accordion top nav bar??

I am using PixoPoint Menu Plugin (and love it!). However one of my menu items has 20+ children, making it so that it goes below the bottom of the screen on most browsers. Although one could use the mouse scroller to go down, this is not something everyone uses or has. What I would like to do is make this an accordion sub-menu. This way that one (very long) list of child pages acts like an accordion enabling users to easily scroll through it. Does anyone know if this plugin can do this? If not can you recommend one that does?

I do not want a side bar accordion menu, I need a top nav bar menu. Any recommendations?