In the exercise of powers authorized by any act of the General Assembly or the Constitution of Maryland, other than the law making power vested in it by Article XI-A of the Constitution and the grant of express powers in Article 25A, Annotated Code of Maryland, 1957, the Council shall follow the procedure set forth in such law or section of the Constitution and the exercise thereof shall be effected in the manner prescribed therein. The powers relating to zoning, planning or subdividing shall be exercised as prescribed by law. (Election of 11-4-86; election of 11-8-88.)