Creating Misc Invoice with Shipment Invoice

Our repair department has become an authorized warranty and repair shop for a vendor. We receive equipment from a customer, evaluate if the warranty is valid, repair the unit, ship the unit back to the customer with a $0 dollar invoice created. We are then creating a Misc. Invoice to send to the vendor so we can be paid for the parts and labor. Currently, this is Misc. Invoice is created manually, but I’m being asked if can be automated.

The only thoughts I currently have are to create a Function triggered by a BPM. Once the $0 customer invoice is created (with a vendor warranty checkbox = true on the Order/Job/Pack/Invoice) the function creates the Misc. Invoice and adds lines (Model Number repaired) and Misc. Charges for the Parts and Labor.

Does this sound like the best approach? We are on 10.2.600.16, so I don’t have access to something like Automation Studio.

Has anyone else needed to do something similar? If so, how did you make it work?

Thanks in advance.