well to answer the question partially for you:
if you can run MW2 or Black ops on it, you'll be able to run MW3.
heading from that, 9400M Review
(scroll down for bench marks)
doesn't look like it will play, since it had questionable performance for MW2 on lowest settings.
bottom of the line is, you need a dedicated GPU to play video games. Yours is an integrated one, so don't count on good performance