Dear Fred,
I see what you mean now.
This is not possible. You would need two menus to achieve this. One on the left and one on the right.
If it is really, really important to have those menus on the right and on the left, you can try with Custom HTML and make the navigation manually.
Also have a look here:
http://laythemeforum.com:4567/topic/2144/fade-effect-smooth-transitions-links-via-custom-html/2
This is the only solution I can think of now.
I hope that helps a bit!
Best!
Marius