Question About “The_Content” Filter Hook

Hey all! First off, please be gentle. I haven’t coded much of anything since college, so I’m a bit rusty. I apologize in advance if there’s an obvious answer to this.

I’m designing a site where I would like the users to be able to enter a “secret code” into a box in the sidebar to access hidden site content. This would bring up embeded flash videos, text, or images depending on the code entered.

It looks like the simplest way to do this is with a WordPress plugin. I understand how to accept the form data, do a database lookup, and spit back out whatever I have in the DB associated with that word.

My issue comes with how the WordPress hook will handle it. Ideally I’d like the visitor to see what looks like just another WordPress page (only w/ the hidden content).

It looks like I need to hook into “The_Content”, but if I do that I think that the output will vary depending on where the user enters their code. For example, if they enter the code on the main blog page then the output from the plugin will repeat itself for every entry displayed.

Does anyone have a suggestion of something better to hook in to? I looked through the hooks but nothing seemed better. Sorry if this is a bit confusing.