I'm guessing you have a Lee scooper, only company that I know of that does that. Anyway, Lee always lists it loads in grains, then gives what they call VMD (Volume/Mass Density I think is what it stands for), so that you can figure out how much volume will equal how many grains of a certain powder. So back to Algebra:

Volume(in CC's) divided by Mass(in grains) = VMD

Multiply the grains by the VMD to figure what the volume is needed to get that weight (or mass) of powder. Or divide VMD by the volume to figure what it is in grains. The scooper will have a number on the handle that is it's volume in cubic centimeters. Only problem is that it's not that accurate, powders change from batch to batch, and different powders have different VMD's, and to get the right volume you might need several different scoopers of different sizes. Get a good scale, they aren't that expensive if you figure in the added safety and precision you get with them.