Asterisk and A2billing Customization

Hi, Candidate should be familiar with A2billing + Asterisk I need calling card customers to be able to save their pin to their CID by pressing #15## after dialing the pin. and after the credit is over the save pin be removed. This should only be done for certain groups of client. (For eg our account selling should have the feature of the disassociation of the pin when the balance is zero as they top up credit instead of buying cards). Also an option of removing the pin by #16##. We also need agents console to be able to add speed dial (same as admin console). Regards,