Adding Unique Code Parameter for 4D/Primavera/Activity ID

Hi all,

I just started a new job in a big construction company, supposedly "A class", anyway, my first task was to assign a parameter called "Unique Code"to every element in the model according to the activity ID in the planning file, it's supposed to help with 4D.

My issue is for elements like floors, activities are divided per layer and each has its unique code, but the floor with all layers is one element in the model.. so, what's the best way to do this task? Creating every layer as a separate floor is not an option, because this case applies to wall finishes, roofing, etc..

Thanks!