Mich. Comp. Laws § 600.410

Sec. 410. A plan of concurrent jurisdiction adopted under this chapter shall not include a delegation of any of the following: (a) A power of appointment to a public office delegated by constitution or statute to the circuit court or a circuit judge. (b) A power of appointment to a public office delegated by constitution or statute to the probate court or a probate judge. (c) A power of appointment to a public office delegated by law to the district court or a district judge, unless that power of appointment is delegated to a court or judge other than the circuit court or a circuit judge.