Printing labels based on # of Close Container actions

I have the following Print situation in Dynamics 365:

For Every "Close Container" I need to print a shipping label, and for every 4 "Close Container"(s) I need to print a Pallet label (4 containers to a pallet).

I have ZPL labels created in my Document Routing Layouts but I'm not sure there is a way to count "Container Close" actions and select the correct label for each 1 and each set of 4.

This isn't so much a label configuration issue as it is a Dynamics issue.

I've created the label code and it works. I'm just fuzzy on whether there's a counter or some-such thing which would let me control the print process based on actions in Dynamics.

CH