After you load my script you have to make sure scroll lock is on; then type Ctrl-Alt-R (for "rename") - that will also set the focus on mouseover with 0 delay - and rename your windows to A1 and A2, only after that it will send the keys to both - remove scroll lock after your did that - then hit pause; login in each window; get in game and it will broad cast all keys but movement ones (as you should follow on the other toon)

Yesterday on the stream I walked Souca through the setup... let me see if I can find the times and make a clip...