Easy, that is a relative term.  You will need a formula to break up the date (month({datefield), day({datefield}), year({datefield}) ) then put it back together as a string.  The tricky part will be the day (1st, 2nd, 3rd, etc.).  With a select-case statement(could use a nested if, but this is cleaner), you will need to determine what day of the month corresponds with the suffix (not sure if that is the correct term).  So here is the start of a rough draft