The provisions of the Illinois Administrative Procedure Act are hereby expressly adopted and shall apply to all administrative rules and procedures of the Office under this Act, except that, in the case of conflict between the Illinois Administrative Procedure Act and this Act, the provisions of this Act shall control, and except that Section 5-35 of the Illinois Administrative Procedure Act relating to procedures for rule-making does not apply to the adoption of any rule required by federal law in connection with which the Office is precluded by law from exercising any discretion.