You would have to make your own page if you wish to have your CP link go to another page. A template_hook is just a way to insert html without modifying the actual template. You would write a plugin which inserts html at the location of the template_hook. There are articles on this in the articles forum.
If you have to write your own page, you can read one of these articles -
How to create your own vBulletin-powered page! (uses vB templates) or
[How-To] vBulletin API Basics: Creating Custom Pages & Misc.