Ordering different number of prints for each image

s there a way to order different number of prints for different images?

Say I want to order a print of all my images in a collection in 4x6, simple enough.

Then I want to order some of those also in 8x10 format, also simple enough.

But what I can not figure out is how to order say; 3 copies of image #4 in 8x10, 2 copies of image #5 also in 8x10, and 10 copies of image #14 in 8x10.

Something I´m missing?

Any help is appreciated.

Thanks in advance.