945.31  Restitution and other payments.--The department may establish bank accounts outside the State Treasury for the purpose of collecting and disbursing restitution and other court-ordered payments from persons in its custody or under its supervision, and may collect an administrative processing fee in an amount equal to 4 percent of the gross amounts of such payments. Such administrative processing fee shall be deposited in the department's Operating Trust Fund and shall be used to offset the cost of the department's services.