SEO conflicting URL issue

Hi,

I have a problem with an SEO conflicting with module names.

1. The main menu option at the top is named 'Product Range' which links to the url 'product-range.html' and shows a product list for all the categories.
2. But I have also added a sub category list in the same section which links to other product lists for each separate category within 'Product Range' -> 'Seperate Category' etc.

The problem is that in order to keep main menu 'Product Range' highlighted I have used the

'product-range/category/listing/15-seperate-category.html'

which doesn't seem to work. The only time I can get it to work is change the url to

'product-ranges/category/listing/15-seperate-category.html'

but then the top menu no longer highlights. Forgot: In order for the url to stay the same I have given both modules the same 'alias' name

cheers for any help.

UPDATE:

The way getting something which I thought was close by more or less placing a product listing module inside the product listing link/page. Worked until you select a individual product.

Also had to edit the category listing_list display line of code from:

if($found == $row->category_id){
$class=' current active';
}

to:

if($found == $row->category_id && $_SERVER != '/product-range.html'){
$class=' current active';
}