And don't use BA.com to book MAD-HAV on Iberia - it'll cost you hundreds in BA fees, even though it is an Iberia flight.
Make sure you have an IB+ account and transfer the avios over to there and then book direct with IB avios for the IB flight.
ps. Much higher "visa" fees for flights from USA to Cuba. Perhaps fly MAD-HAV HAV-MIA and then MIA-MAD, all transatlantic on Iberia. (and remember one-way ex-USA in BA CW or F on avios carries HUGE surcharges!)