Надо так:

WinApi.keybd_event(SHORT(CHR(WinApi.VK_CONTROL)), SHORT(CHR(WinApi.MapVirtualKey(WinApi.VK_CONTROL, 0))), {}, 0);
WinApi.keybd_event('C', SHORT(CHR(WinApi.MapVirtualKey(ORD('C'), 0))), {}, 0);
WinApi.keybd_event('C', SHORT(CHR(WinApi.MapVirtualKey(ORD('C'), 0))), WinApi.KEYEVENTF_KEYUP, 0);
WinApi.keybd_event(SHORT(CHR(WinApi.VK_CONTROL)), SHORT(CHR(WinApi.MapVirtualKey(WinApi.VK_CONTROL, 0))), WinApi.KEYEVENTF_KEYUP, 0)