If you a member of Starwood Preferred Guest (SPG) programme and have a balance of 22,000 Starpoints, you will easily be able to obtain 27,000 Asia Miles by doing a transfer. With SPG transfer, you get an addition 5,000 bonus FFP miles when you transfer 20,000 Starpoints. Other options with hotel programmes include transferring Marriott Rewards points to Asia Miles if you have an account with Marriott with a significant account balance.

Other than that, you might have to resort to buying the miles.