[ MoveCursor line column;  ! 0-based postion on text grid
    if (gg_statuswin) {
        glk($002F, gg_statuswin); ! set_window
    }
    if (line == 0) {
        line = 1;
        column = 1;
    }
    glk($002B, gg_statuswin, column-1, line-1); ! window_move_cursor
    statuswin_current=1;
];