Yo dawg, he wants to put a swf in his capx, so he can flash, while he constructs.
Actually, not sure exactly what you want to do here. Using flash within the canvas kinda negates the idea of "no plugins". Then if instead you wanted a way to convert that animation to something C2 could use your kinda out of luck as it converts all images to png. Unless its a vector, which might be doable in the future, but the animation of vectors is a bit iffy.