The CAP is a central answering position application with one unit having 48 buttons. The good news is that my technician managed to locate a CAP module and hooked it up to a 7324 on the customer's IPO here on the bench. This is what I learned as it relates to the IPO:
The 7324 has handsfree on the bottom right button of the phone therefore the button numbering on the main phone is 0-23 with button 0 as handsfree/mute and button 1 being on the bottom right row just above the handsfree. Button 23 is on the top of the left row of the phone itself.
The CAP numbering begins with 24 and starts at the top of the left most row and numbers down the row to 35, then 36 begins at the top of the next row to the right, etc. I hope this helps someone else out down the road.