Create Proforma Invoice from Service Confirmation without complete/finalize confirmation

Hello, 

I americium moving connected Service Orders (on SAP Public Cloud) and my lawsuit request to validate the invoice with his lawsuit earlier to nonstop to billing department. 

I americium presently investigating and the lone mode I tin make immoderate billing papers is from a billing request, and this measurement is lone disposable aft confirmation is complete/final.

This presumption is not the cleanable 1 for my client, due to the fact that immoderate feedback from the lawsuit volition not beryllium capable to beryllium changed connected confirmations if the presumption is already finished. 

There is immoderate anticipation to grip a transcript regularisation that allows maine to make a Proforma invoice from the confirmation with a presumption "open"? 

Do you person immoderate different ideas?