How to open previous iMovie 09 Projects- don't appear in the Project Pane!

I have a lot of iMovie 09 Projects that I have done but they no longer appear in the Project Pane. They are still on my external mac-formatted hard drive, but I can't get them to open in iMovie. I remember moving them to my external hard drive within iMovie at one point and I have a bad feeling I might have removed them from iMovie so they wouldnt slow it down... All the events are gone as well, but still reside on my external drive.

How can I re-open older projects once they don't appear in the project pane any more? They are still in the designated "imovie projects" folder on my hard drive...

Thank you