wordpress - how to make a page with no parent appear in a subnav menu

I have a page with a Parent of Main Page (no parent), so that it appears in the main navigation of the site. However, I also want to get to this page through one of the options on a drop-down menu. If I set the parent to that Nav page, it appears in the drop-down but then disappears from the main nav list. For example:

Main Nav:

Dogs Cats Birds Fish

Sub-Nav for Cats:

Siamese Tabby Fish

I want Fish to appear in both the main nav and the "Cats" subnav. How??

Here is how I'm currently displaying the list:

wp_list_pages('title_li=&depth=2&exclude=12,342')

You could try the 'include' parameter for wp_list_pages, see what happens. If that does not help you will probably have to add a link after the wp_list_pages call manually and keep the original in the submenu.