Can't get key fob for a sprinter

Well after thinking long and hard about the inability to get a replacement key fob from MB, I remembered that I had an alarm system installed in my rv and it was activated when I used the one still working key fob to set it and/or lock the doors. So I thought, I wonder if I can get a remote/key fob for the alarm system which would in. turn also lock and unlock the doors? So after visiting the shop that installed my alarm system, they confirmed that yes, it would work. I now have an appointment for this Friday wherein I will pay $49.99 for a new alarm key fob and about 1/2 labor to program the fob to my alarm/door lock system. Am I happy or what!!!