Is there a way that you can call into your PBXES server from a external number and then with some key combination be able to turn around and dial out from the PBXES server with your office number? I know some old phone systems were able to do this so you could look like you are calling from your office number but are not there. I know there are apps out there to be able to have an ext tied to your phone and make calls from them. However the voice quality is only as good as your cell service and calls could drop as well.
Thank you