I know that you've met this problem. You have a lot of bitmaps in your library and you have to edit all of them one by one. There are several solutions of this problem. One of them is to use JSFL. There is another one - an extension for Flash provided by ArsThanea. Check it out here.

During the creation of the latest changes in my portfolio site, I needed to duplicate a loaded image that has to be placed as a material in papervison3d's cube. We don't have duplicateMovieClip in AS3, so we have to use another technique.