Creating animation with preloader

I have a preloader that shows the percentage being loaded. Its only 1 frame. I got it from this website. I need to have an animation running at the same time as the loader is running- i know how to make the animation but its many sparkling stars over tons of frames, each sparkle/star taking about 4-5 frames. Whilst the preloader is only 1 frame. How do I do this? Thanks…