See Robert Scott's reply in
this thread. I've changed a few of mine where I was doing the same thing in VA, one character at a time, and this works a lot better. Basically it's reading a pre-typed txt file you make and dumping it into the clipboard, and then VA uses paste (Control-V) to put it into the chat window. All VA has to do is open the chat with the set hotkey, call this app, and then afterwards hit Enter to send.
I've been trying to see if I can generalize it even more, so that VA uses a prefix and then a suffix, and the suffix determine what text file is pulled up. No success yet, but even if you had to make a long list of suffix commands with their files, it's still a lot more graceful, and easier to modify the message, than the other way.