LEDs?

I wish to create a program as a sort of homage to Blinkenlights. There are a number of LEDs on my computer, and I'd like to know how to turn them on and off in C++. Specifically, the power light, the 'hard drive activity' light, the 'floppy drive' and 'cdrom drive' activity lights, and the three lock lights on the keyboard (Num Lock, Caps Lock, and Scroll Lock).

If anyone can tell me how to manipulate any of these lights through my code, it would be greatly appreciated.