You can find your screenshots from your AHII-folder (default: "C:\Program Files\Hitech Creations\Aces High II" or something - sorry, I've never had it in the default location), you've got to edit (resize, convert to jpeg, et all) them in a suitable program (MS Pain or something more adept - GIMP, Paint Shop Pro, Photoshop or such).
I haven't edited any films, but Windows Movie Maker (comes with winXP) should be enough.. Do a search here in the f&s forums for more detailed guides,