how to click explorer through PostMessage

I can not click on explorer in Windows 10. My Message:

private static IntPtr CreateLParam(int LoWord, int HiWord)
    {
        return (IntPtr)((HiWord << 16) | (LoWord & 0xffff));
    }

SendMessage(hand, 0x00000020, IntPtr.Zero, CreateLParam(x, y));

This request does not work for explorer. But it works for other windows.