While the rice is steaming, combine the coconut milk, water, sugar and salt in a large saucepan and heat until the sugar and salt are dissolved, stirring continuously. Remove from heat and set aside.
Drain the soaked rice and place in a steamer over a pot of simmering water. Cover and steam until the rice is soft, about 20 to 25 minutes.
Put the rice in a large saucepan and cover completely with water. Soak overnight or for at least 6 hours.