This is pretty easy. The property settlement should stipulate that the account holder owes the other party awards of her choice (subject of course to availability from UA and the other T&C of MP) equal to 475,000 miles as of the date of divorce, to be used within a stipulated time frame. As ButIsItArt notes, MP will not recognize any such claim - it's a matter for the parties to settle w/o help from UAMP.