HOWTO: generate CRTL-ALT-DEL for a programm?

Hi I have to simulate the CRTL-ALT-DEL user input from my program.
I tried:
keybd_event( VK_MENU,0,KEYEVENTF_EXTENDEDKEY | 0,0 );
keybd_event( VK_CONTROL,0,KEYEVENTF_EXTENDEDKEY | 0,0 );
keybd_event ((BYTE)VK_DELETE,0,0,0);
keybd_event( VK_MENU,0,KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,0);
keybd_event( VK_CONTROL,0,KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,0);

but it doesn't work.

Any ideas?

Can't be done using the API code (Security Design). I think PC Anywhere does it by changing some NT drivers.