Chargeback / accounting include licencing costs

We are running our first opennebula deployment and are looking into the accounting / chargeback options. It seems that you can assign a per hour cost to memory, cpu and disk.
Some vm’s run Windows that has some additional costs on a per vm basis, how could this be defined?
It is not related to the amount of cpu, ram or disk.

I don’t believe opennebula has such functionality , we incorporate additional costs into our own billing.

Use the API to get showback and also the template id
Then based on the template id add the additional cost if that makes sense.