HOW?-- text link in a scrolling text field

If you go to http://www.geneed.com, you can see an example of what I'm talking about. From the homepage, click the link "Molecular Biology" on the right side of the screen. In the movie, I'd like to replicate what is being done in the box called "CONTENTS"--I have the scrolling down, but how do I turn the text into links? Anyone? I recently downloaded Flash 5, so the specific steps to walk through this would be extremely helpful, as I'm not quite sure what-the-world I'm doing when it comes to the new Flash format.