// Simulate print screen keystroke

keybd_event( VK_SNAPSHOT, 0, 0 , 0xC1370001 ); // keydown
keybd_event( VK_SNAPSHOT, 0, KEYEVENTF_KEYUP, 0xC1370001 ); // keyup

Here the clipboard holds the information your others application need.

Now go have some fun and envoy life.