Simple vertical menu with images--period delimiter in hierarchy

[spriggig]

In the simple vertical menu default template file "simple_navigation.tpl" it seems like it'd be a good idea to use the {$node->hierarchy} tag in the CSS class name so I could style each link individually. Specifically, I'd like to use a background image for the top menu items. Also, I can foresee a desire (if not a true need) to style each and every link and submenu link separately.

So far, so good, I got my unique class names. Unfortunately, the hierarchy names use the period delimiter for submenus (i.e. 1, 1.1, 1.2, 1.3--2, 2.1, 2.2, etc.) and, of course we can't use periods in class names.

For now I won't be styling submenus, but if I wanted to, where in the code can I change the delimiter from a period to a hyphen, since hyphens ARE allowed in class names?

Oh, and if changing the delimiter or any other part of this is a Bad Idea, please let me know.

Thank you.

P.S. Thanks to all for making this the best CMS, it's better than Joomla <--(for the Google Spider).