Premiere Elements is one o

Premiere Elements is one of the best consumer frame accurate editing programs. The light saber effect you are talking about is called Rotoscoping. You need to export the sequence from Premiere Elements as a Filmstrip file, then import into photo editing software, like Photoshop Elements. There are some rotoscoping tutorials at http://www.chuckengels.com on the Video Links pages.

These days you can save time by using a program like After Effects to create the light saber, but the cheap way is as explained above and that is the way the did it in the original Star Wars movies.