CANADIAN police are hoping to solve the murder of the daughter of Immigration Director Laurence Leung Ming-yin by broadcasting a re-enactment of the killing of 22-year-old Sylvia Leung Sze-hon on Vancouver television stations from today. The most recent segment of the Royal Canadian Mounted Police's one-minute Crime Stoppers programme, showing how a man stalked and killed Sylvia Leung with a crossbow in the car park of the British Columbia Institute of Technology on January 24, will be aired 24 times a week this month and August. ''We're looking for assistance from the public - there's someone out there who knows something,'' said police staff sergeant Michael Eastham. He said the re-enactment would follow a Sylvia Leung look-a-like from the school activities centre to the car park where a metallic bolt was fired through the victim's shoulder, and show her stumbling along the sidewalk back towards the school. The 25-week investigation had uncovered no new leads, despite a $1.8-million reward posted in Vancouver and Hongkong.