How to click by coordinates in window? (Python)

Question

I'm writing a script and I need to simulate click by coordinates in specific window. How can I do it without window maximizing?

I tried to use win32api library:

lp = win32api.MAKELONG(0,0)
win32api.SendMessage(hwnd, win32con.WM_LBUTTONDOWN, win32con.MK_LBUTTON, lp)
sleep(0.5)
win32api.SendMessage(hwnd, win32con.WM_LBUTTONUP, 0, lp)

It doesn't work. Also I tried to use pywinauto, it doesn't recognize the controls (the window is game)