parsing Phone numbers

I need to parse a phone number into area code and phone number.  I found business function B011903, which appears to do just that; however, it doesn't appear to work.  I can't find any documentation on it and it doesn't appear to be used any app or UBE (using Cross Ref Util).  I'm trying to avoid have to write custom logic to do it.  Any info on this business function or another parses phone numbers would be appreciated.

thanks