While After Effects is really what you want for this type of stuff, depending on what you want to do there are some things you can do within Premiere it'self.

You can add colour mattes above the video track and use the garbage mattes to make shapes then animate these shapes over the video.

Track mattes can also be used in a similar way.

You can also export the section of video as a filmstrip, open it up in Photoshop, and go from there.

David.