selectmenuitem ('<window name>', '<menu hierarchy>')
Selects the menu item specified.
Refer: http://webcvs.freedesktop.org/ldtp/ldtp/src/menu.c http://webcvs.freedesktop.org/ldtp/ldtp/src/check-menu-item.c
http://webcvs.freedesktop.org/ldtp/ldtp/src/menu-item.c http://webcvs.freedesktop.org/ldtp/ldtp/src/radio-menu-item.c
With respect to gedit menu structure
selectmenuitem ('*-gedit', 'mnuFile;mnuNew')