The metric system's version of MOA is called a MIL. An MOA is equal to 1 inch at 100 yards, while a MIL is equal to 1 centimeter at 100 meters. If you use the MOL, simply measure the distance between the aim and impact in centimeters instead of inches. If your red dot uses MILs,  convert your aim-to-impact difference from inches to centimeters. Determine how many MILS per click your reticle requires to adjust, and zero at a known distance in meters rather than yards.