Has anyone done the Hola Madrid stopover program via an award ticket? We are thinking about doing 2 nights in Madrid on the return segment. What I am trying to figure out is,

1. Can the stopover be added to an existing trip? (if I book a flight with a layover but not a stopover, will they change the date of the second segment to allow for the stopover?)
2. Can the booking be done online or must it be on the phone? (there is a section of the Iberia site that allows for booking the stopover, but it only seems to work for cash tickets)

Thank you!