I have a notional design to accomplish this, see attached. I am not planning to use for now the rain sensor, so I will be using it to detect if the garage is open or close. Running the once program for 2 secs for the specific station should activate the relay no different than pressing the close/open button. The only potential problem is if the door is left open and a sprinkler program is about to run, but in my case, I water at night so the likelihood of this coincidence is low.