Uploading own video to iMovie on iPhone

Hi, I hope you can help with this urgent query!
Im using iMovie on the iPhone and can make normal videos no problem. What Id like to do is use a little intro video that Ive created on my laptop, upload it onto my iphone and use that clip at the beginning of each video I create on the iPhone.
Ive managed to convert the intro clip to an iphone format and upload it onto the phone, where it appears on my ipod. But in iMovie it is not given as an option to insert into a new project. Am I uploading it in the wrong format and, if so, what format do I need and how do I do that? Or is it simply not possible?
Please help!
iPhone iPhone OS 3.1.3