Show only 1 category of many

Hi all, first post here. I'm looking to modify the categories module. Currently my site is set with 5 horizontal categories which will never change.

Example:

Toys | Food | Cars | People | Furniture

Each one with their respective links

<a href="index.php?route=product/category&path=35">Toys</a> | <a href="index.php?route=product/category&path=36">Food</a> .....etc...

Each category has 3 sub categories which have 3 products each

Example:
Toys > Power > RC Car
Toys > Power > RC Plane
Toys > Power > RC Truck
Toys > Non-Power > YoYo
Toys > Non-Power > Top
Toys > Non-Power > Whistle
..etc....

Currently when clicking on one of the horizontal links all of the categories appear in the module box on the left with the selected category being expanded.

Example, when clicking horizontal link for Food the following appears in the categories module

Toys
Food
> Burger
> Taco
> Hot Dog
Cars
People
Furniture

I would like for when a horizontal link is click ONLY it's sub categories appear in the categories module

Example: Clicking, Toys shows only the following in the box:

Power
Non-Power
Educational

Whatcha think?