How to wake from sleep programmatically if lid closed?

I want to wake system from sleep programmatically, is there any way to do this?

I have read following link: http://developer.apple.com/mac/library/qa/qa2004/qa1340.html

this only talk about getting notification , but not sure is there any way to wake system from sleep?

I appreciate some thread to the information...

Update:

As per the suggestion I tried with IOPMSchedulePowerEvent

Code I have used:

NSCalendarDate  *timeIntervalSinceNow = [NSCalendarDate dateWithTimeIntervalSinceNow:40];
IOReturn result = IOPMSchedulePowerEvent ((CFDateRef)timeIntervalSinceNow, NULL, CFSTR(kIOPMAutoWake)); 

Result:

It fails in MacBook if lid closed

Am I doing some thing wrong or Any solution?