Except as provided in sections 2-15 and 4-14, the Comptroller shall not draw any order on the Treasurer for any sum to cover any charge for expense for travel to and from his home and the Capitol, or any personal expense while at the Capitol, of any officer or employee of the state having an office in the Capitol; or for any sum charged for clerical services rendered such officer or employee other than services rendered at the office of such officer or employee at the Capitol, except for clerical or special services approved by the Commissioner of Administrative Services.