Delayed Auto-Attendant using Embedded Voicemail?

First Create a Short Code Like:
Code: *98
Feature: Autoattendant
Telephone Number: AA:XYZ This being the Name you gave your AA
Line Group ID: 0

Next Create a Virtual User and in the "Forwarding" Tab Click "Forward Unconditional" and "Forward Hunt Group Calls" and in the "Forward Number" field enter *98

Next Create a New Hunt Group, Set the Ring Mode to Sequential, then in the "User List Box" add the Virtual User you just created.

Next, in your Main Hunt Group, the one that "rings" the phones that you want to ring 2 times, Add the hunt group you just created in the previous step to the "Overflow Group List" Box.

The "Overflow Time (secs)" field will govern how many rings will be heard before the call goes to the Auto Attendant. (about 5 seconds per ring give or take a second)

NOTE: Make sure you have built an incoming call route with a destination going to the Main Hunt Group containing the users phones you want to ring before the AA answers.