§ 13-c. Assistant adjutant general for army. The governor, upon the recommendation of the adjutant general, may appoint an assistant adjutant general for army 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 brigadier general during his term of office. He shall have such duties as may be prescribed by the adjutant general.