PT Invoice Do Not Print Zero Items

In my business I take sales orders and usually only ship part of the order. I want to be able to print an invoice off of the sales order that shows ONLY the items that I am invoicing for at that time. Currently, when I print the invoice, it includes ALL items on the sales order which is very confusing to my customers. Is there a way to customize the invoice so that only line items not equal to zero be printed? Thanks! Nini