Heat cream and coconut to boiling in medium saucepan; simmer 5 minutes. Cool to room temperature. Strain through strainer lined with double-thickness of cheesecloth, pressing coconut firmly to extract all the cream. Discard coconut and reserve the cream mixture. Heat milk and sugar just to simmering in a medium saucepan, stirring occasionally to dissolve sugar. Whisk about 1/4 cup hot milk mixture into the egg yolk; whisk yolk mixture back into milk mixture. Cook over medium heat 2 minutes, whisking constantly. Strain mixture through fine strainer. Stir reserve coconut-cream mixture into milk mixture; stir in coconut extract. Cool to room temperature then chill. Freeze.