Get the Microsoft media center remote + usb IR receiver.
(Kinda like this:
Amazon.com: Windows 7 Vista XP Media Center MCE PC Remote Control and Infrared Receiver for Home, Premium and Ultimate Edition: Electronics )
When you set it up, it should be able to put the computer to sleep / wake from sleep. If not, there is a checkbox to allow wake from sleep in the device manager somewhere.
Used that for my media center, and it worked just fine, never pressed the power button on the machine, only used the remote. Wasn't a laptop, but same diff.