Anything you can do with an inline function, like triggering commands and modifying variables, can be done by a plugin, so if you write a plugin that communicates with another process it can run in the background and handle that for you.
While a plugin can be triggered by an explicit "Execute an External Plugin Function" action, you can just as easily have something running as soon as the plugin loads(which would normally be when VoiceAttack starts, barring explicit disabling of your or all plugins).