Custom menu function.

Howdy all.

I need to extend the wp_nav_menu function a bit.

I have a menu structure like this

<li data-slide="1">Home</li>
<li data-slide="2">About us</li>
<li data-slide="3">Portfolio</li>
<li data-slide="4">Team</li>
<li data-slide="5">Blog</li>
<li data-slide="6">Services</li>
 <li data-slide="7">Contact</li>

and I need those numbers from the “data-slide” attribute to be dynamically changed, if a user rearrange the menu in Appereance -> Menus.

If somebody could help me that would be great.

Regards