I do not know the game, but the internal windows send messages to move the mouse. They are sent by calling the SendMessage() API for the application. In C #, will you have to either use the same Win32 API directly, or perhaps by creating / sending an event? Not sure how to send the event to another running application.
The Win32 SendMessage () API call defined in C # will look like this:
[DllImport("user32.dll")] public static extern int SendMessage( int hWnd, // handle to destination window uint Msg, // message long wParam, // first message parameter long lParam // second message parameter );
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