§ 13-b. Deputy commander of the New York army national guard. The governor, upon the recommendation of the adjutant general, may appoint a deputy commander, New York army national guard who shall serve at the pleasure of the governor. He shall be appointed by the governor from among the commissioned officers on the active list of the army national guard and, while holding such title, shall have the grade of major general during his term of office. He shall have such duties as may be prescribed by the commander, New York army national guard and shall act in the place of the commander of the New York army national guard during his absence or disability.