Active Directory - Outlook - Personal Contact - Phone Information Problem

We are using Active Directory with Exchange.  In my GAL I have a field for Telephone Number that has our extension number in it.  However, our CTO now wants another field in AD that has our Direct Dial number in it also.   The kicker is that he want to have that number populate into his person contacts when ever he saves an address book object from Outlook to his contacts.  We can use the Home Phone filed but he does not like that name.   Is there:
1. Any way to change the name of the Home Phone filed so that it will populate to the same name with some one copies it into their personal contacts?
or
2.Another fileld that we should use for this.

Just a note is that the one specific reason for doing this is for his blackberry.