mask layer in swf file?

[Secret Agent]

note: couldn't find any flash forum so I am posting here.

How do I put a "mask layer" (image) over an animated swf movie? I want the image (my logo) to be static on all frames. I'm using Flash MX. I opened the swf and have no ability to do anything as it is protected. Any way around this?

I have an animated flash tour of a bulding. I want to add my logo to this swf file. The company that designed the flash tour wants $3k for full branding. I'd rather add this layer myself for the logo.

[belama]

Have you tried to use a swf flash decompiler? It would decompile the file so that you can modify it. But you might have to pay for these decompilers to decompile the swf file completely.