creating extra space between last subcat

Hi,
I have a menu with cats and subcats
example:
cat1
subcat1a
subcat1b
subcat1c
cat2
subcat2a
subcat2b
subcat2c
cat3
subcat3a
subcat3b
subcat3c
etc

I want to have an extra space/seperator or div between the last subcat and the categorie under it.
So an extra space in this example between subcat1c - cat2 and subcat2c - cat3 and subcat3c - etc

Where can I insert an seperator, div or <br />

The simplest way to do this is with the 3rd party module "categories dressing" available in the downloads section

kobra:

The simplest way to do this is with the 3rd party module "categories dressing" available in the downloads section
I hoped for a much easier way...just with a addition in the tpl_categories.php.
The "categories dressing" is a very nice addon, when you want to change the whole menu....I just want to change a little tiny thing.

Thnx Kobra, I'll give it a try...but more, hoping at another solution.