Line animation - from a dot to outline of graphic?

i had a talk to a friend of mine as to how this would be achieved. i can’t seem to achieve the answer.

basically what i want to do is this. the screen is basically empty initially in the animation, with only a dot. but as soon as the dot blinks, i want it to begin moving, and eventually outlining the shape of a human, and also outlining background details. afterwards, i would like the real photograph to fade in, behind the outlining, to create a photograph with the edges basically all outlined.

really appreciate it. i have a string of other things i’m looking at too. i have a client interested, and our flash team just left for further persuing their graphic design careers at york university.

thanks,
danny