Hi @billbillr79 welcome to the community and thanks for posting. The call control pin is the same as the remote access pin and the only way to change it is to enter the current one on the handset. As you've lost it I'm afraid your only option is to do a factory reset which will remove the contacts.
is there a facility on phone to export contacts to external storage then reset phone then import contact back to phone
Hi, I did a Base only reset on my cordless advanced BT phone and it didn't remove any contacts. I was then able to reset the pin to gain access to call control with a new pin number. I phoned BT help line and I was told to unplug the hand set and leave for 10 minuets and it would reset, needless to say it didn't do any good. I phoned again and got through to someone who new what to do. Bill