Creating frames in movieclips with AS?

Is it possible to add frames to a movieclipp with actionscript? I’ve got many sprite animations with varied frame counts. What I would like to do is create a movieclip in actionscript and add frames based on the animations amount of frames.

eg.
Animation A
walk1.0.body.png
walk1.1.body.png
walk1.2.body.png
walk1.3.body.png

Animation B
alert.0.body.png
alert.1.body.png
alert.2.body.png

Instead of seperate movieclips in the library for each with the right frame counts is it possible to dynamically create a movie clip and add the frames all in actionscript?