Mich. Comp. Laws § 767.7e

Sec. 7e. If the court of appeals convenes a grand jury with jurisdiction over 2 or more counties, the court of appeals shall do all of the following: (a) Designate a judge of the circuit court or of the recorder's court to preside over the grand jury proceedings. (b) If the petition to convene the grand jury was filed under section 7b(2), designate the prosecuting attorney of 1 of the counties over which the grand jury is to have jurisdiction to assist the grand jury. (c) Designate the counties from which the jurors shall be drawn from among the counties over which the grand jury is to have jurisdiction. (d) Designate the number of jurors to be drawn for the grand jury and the number of jurors to be drawn from each county. (e) Designate the locations for the grand jury proceedings.