You need to set the real mouse cursor instead
SetCursorPos((int)mouse_pos.x,(int)mouse_pos.y); // using windows.h
and for mouse clicks you can do something as follows:
mouse_event(MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0);
wait(1);
mouse_event(MOUSEEVENTF_LEFTUP, 0, 0, 0, 0);