I would like to set up our 911 calls to force a 9,911 when calling the emergency number. we have a lot of false calls from the phone center due to the fact that you only have to dial 911 instead of 9,911. The 911 is set up as a AC1,SPN in ld 90. Do I just remove the SPN for 911 calls to force the switch to accept 9,911 instead of just 911?