category page with links to other categories

I have spent more time trying to figure this out and can't seem to make progress.

For starters, the site in question is: http://www.biadchili.com/

The main navigation menu is based on EZ Pages. The link for the Online Products goes to an EZ Page that has links to each of the product categories.

Each of the product categories is simply the 'default' listing of all products in the category.

For example, Frozen Whole Green Chile goes to
http://www.biadchili.com/index.php?main_page=index&cPath=40

On each category page, the client would like to have links to each of the other 2 categories (similar to the EZ Page)

I tried to create a submenu on the main navigation using the TOC/Chapters feature. However, all this resulted in was adding each of the 3 categories in line with the main menu items rather than as a drop down under the Online Products tab. I did have the EZ Pages display for Table of Contents for Chapters status set to ON. I also had the different categories put into a chapter with the tab Online Products.

I thought there was a simple way to display links to other product categories on a specific category page but I am not finding it.

thanks in advance

I may not have thought this through, but I wonder if you could duplicate the other two categories as subcategories (including products) to each main category, so that the subcat images would display at the top of the product listing.

In other words, if Frozen Whole Chilis is category id 1, the link on the EZ page would lead to /index.php?main_page=index&cPath=1.

But clicking on the Frozen Whole Chilis image that's on the Frozen Chopped Chilis product listing would go to /index.php?main_page=index&cPath=65, but would display the same products.