Here is another approach which doesn't use CallerID or any 'Forward' from the LINE port to the AA. Very similar to that initially proposed by azrobert.
Set the LINE port InboundCallRoute to
{ph,aa}
which should ring the phone and the AA. You want to have a chance to answer the phone before the AA does. Under Voice Services, Auto Attendant is the AnswerDelay Parameter. The default value is 4000 which means 4000 ms or 4 seconds. You probably would like a longer time so increase that appropriately.
