Copying formula down with reverse numbers

Hi Everyone,

I am setting up an awards sheet with many classification and the order of awards is from lowest to highest placement.

I am using

=IF(ISBLANK(Aux!18)," ",Aux!18)

in the first classification but when I try to copy this down the number of course goes up to 19 etc.So I have to manually type in all the references.

Is there a way to have the order reversed. In other words the number goes to 17, 16, 15 etc?

Thanks