New Post: How to combine multiple images into one

I'm new to your tool but am really impressed thus far. My question is.. I have a pre-created .gif file, lets say a animation of snow falling, and a standard .jpg or .png file of a picture of someone. Is there a way that I can use the .gif image as an overlay on top of the .jpg image? It looks like your tool may be able to do that and I'm hoping you'd have a code sample that may show me the way.

Thanks in advance