matty says (3:18 PM):
you can either use a timer to detect
GetAsyncKeyState or use
PeekMessageW along with
WaitMessage and as well the
RegisterHotKey to listen for messages on a custom window for plus!, then when you "hear" that F2 is pressed have a timer start and after 15seconds check to see if F2 is still held, if it is use
PostMessage or simulate pressing F2 to the window using keyb_event.