Presuming it is not possible from the PIC, you may investigate "Tasker" or "ITTT" (If This Then That), both Android applications (I believe ITTT has an Apple version) that automate functions on your cell. For example, Tasker turns off the screen lock on my cell in range of my Wi-Fi and turns it on when I leave range. It also logs onto my website and performs "housecleaning" chores Tuesdays at 9:00pm and notifies Pebble of various telephony conditions. Quite capable of sending (or responding to) specifically worded texts and emails as well... I am confident it would recognize and respond as you wish. Seems like a perfect compliment to Bluetooth automation, even if (sadly) it does not resolve your specific need.