Section 73A. Any employee who by reason of partial disability is entitled to receive compensation as provided by section sixty-nine from the commonwealth, or from such county, city, town or district, and who in the opinion of the head of any department or of any appointing officer, can be suitably employed in such department or by such officer in a position with duties adapted to his reduced earning capacity, may, subject in the case of a state employee to the approval of the division of personnel administration, be so employed at a salary based on his reduced earning capacity as determined by the industrial accident board or a member thereof after a hearing; provided, that no such employee shall be so employed in a position within the classified civil service without the approval of the personnel administrator. The head or appointing officer of the department in which such employee was employed previous to the injury causing his disability, may, subject to the provisions of chapter thirty-one, temporarily employ a person to fill any vacancy in the original position of such employee that may be caused by his disability, pending the return of such employee to full time employment at his regular duties.