how to get from cortina de ampezzo to milano

Line 29 bus leaves twice daily at 1430 and 1530. Takes about 2 1/2 hours to Venice Mestre rail station where there are frequent trains to Milan. You need to make a reservation for the bus.

There are buses at 8:30 and 11:30 to Venezia Mestre station that take 2 hours and 20 minutes.
http://www.cortinaexpress.it/wp-content/uploads/ORARI-ESTATE-2016-Cortina-Bologna.pdf
At Venezia Mestre you can get an express train to Milano Centrale every hour (sometimes more) that take 2 hours and 23 minutes.
http://www.trenitalia.com/tcom-en
At Milano Centrale there are trains every half hour to Milan Malpensa airport taking about 50 minutes.
http://www.malpensaexpress.it/en/