Hi, I got a way to get the call to a cell phone in Mexico:
I have my home phone line with Telmex, it has a digital service called "Follow me", I programmed the alarm to call to my own home, where my alarm is installed.
When I go out of my house, I configure the "Follow me" service to transfer the calls from my house to my cell, then if the alarm triggers, it calls my own home, and the phone company transfers the call to my cell.
When I get back at home I cancel the "Follow me".
The service "Follow me" has a monthly charge, and also the call to the cell gets charged in my phone bill.
Also every phone call to my home, while the follow me is "on", gets transferred to my cell, and gets charged on my phone bill.
It's a little bit troublesome but is the only way I have found to do it.
I hope this helps.