be transferred from the appropriate trust funds of the Office of Personnel Management, as determined by the Inspector General: Provided , That the Inspector General is authorized to rent conference rooms in the District of Columbia and elsewhere. Office of Special Counsel salaries and expenses For necessary expenses to carry out functions of the Office of Special Counsel, including services as authorized by 5 U.S.C. 3109 , payment of fees and expenses for witnesses, rental of conference rooms in the District of Columbia and elsewhere, and hire of passenger motor vehicles