Section 16D½. All monies received by a regional district school committee as tuition payments for nonresident students and as reimbursements from the commonwealth for students who are foster care children shall be deposited with the district treasurer and held in a separate account in the district treasury. The receipts held in such a separate account may be expended by said regional district school committee without further appropriation for expenses incurred in providing education for such nonresident students or for such students who are foster care children.