Hello and hope you all had a great festive break?
This seems like a simple request and I have done this before using other PBX's.
Scenario: We have a customer/doctor surgery using a MiVoice Office250 6.3 that by default when dialling out over SIP trunks do not send a caller ID for patient confidentiality reasons. They would like to use a key to "switch on" caller ID and send the main SIP telephone number when dialling out to some patient that use a service available in the UK called anonymous call rejection.
The SIP provider will accept any CPN we send but I can't work out how to assign this feature to a key the user can select before placing the outbound call.
Thanks for any advice

Aaron