All revenues, refunds, legal settlements, reimbursements, donations, gifts, grants, or bequests coming to the service from any source whatsoever shall be kept by the administrator in a special fund to be designated as the “Children’s Special Health Care Needs Service Fund”, which is hereby created in the state treasury, and all expenses of the service shall be paid by the administrator from this fund. State appropriations to the children’s special health care needs service shall be paid to the administrator upon proper requisition therefor. Any surplus moneys in the fund not currently needed for operation expenses may be invested by the administrator in obligations of the state of Missouri or of the United States of America or obligations guaranteed by the United States of America. Any trust funds in the hands of the administrator may be invested in such manner as may be provided by law, except that any trust funds coming to the administrator with special instructions with reference to the investment thereof shall not be invested contrary to such specific instructions.