This question cannot be answered in a sensible way. A millimetre is a measure of length, with dimensions [L]. A fluid ounce is a measure of volume, with dimensions [L3]. Basic dimensional analysis teaches that you cannot convert between measures with different dimensions without additional information.
Three cups equals 24 fluid ounces.
There are 3 cups in 24 fluid ounces.
Three cups = 24 fluid ounces.
24 mL = about 0.81 US fluid ounces.
1 dl = 3.38140227 US fluid ounces