// код получения Handle окна
string winClass = "#32770";
string windowCaption = "0.0 )Deploy";

IntPtr hWndHar = NativeMethods.FindWindow(winClass, windowCaption);
if (!hWndHar.Equals(IntPtr.Zero)) {
    //NativeMethods.SendMessage(hWndHar, WM_SETTEXT, 0, "key"); 
    if (NativeMethods.GetWindowText(handle, buff, chars) > 0) {
        Console.WriteLine(buff.ToString());
        Console.WriteLine(handle.ToString());
    }
}