Most of the programs on this site include mouse broadcasting. The general process is that you can initiate the spell with a key, but you have to click in the toons window to cast the spell.

There are 2 approaches

1) Initiate the command and broadcast the mouse click.
2) Initiate the command and click in each window.

1) is obviously the quickest, but I sometimes use 2) if my characters are not stood together / facing the same direction or if I want to spread the AOE over a bigger distance.