There's a new program called BotSquad that allows you to define hotkeys that can trigger actions in one or more windows on any PC on your network. A single keypress can perform the same action or different actions in several instances of a game.

It just went into public beta yesterday. You can download it for free from its website:

www.botsquad.net

(I'm the author of this program -- I hope I'm not breaking any rules by posting a notice for the program here.)