No one knows the future foreign currency exchange rate. Though if you go online or the streets and look for currency exchange rates now, it should give you a rough idea.
http://www.ratesfx.com/rates/converter.php
As of Wednesday, September 19 2007, 16:00 EST DST (2007-09-19 20:00 UTC)
HKD1 : 泰銖 4.11