Usage Billing with Quantity included from Product Qty

[dadeitch]

I'm trying to figure out if there's a way for my scenario to work.

I want to use metric/usage billing as overage billing for my quantities set through Configurable Options ... NOT the Quantity Included set in the metric/usage billing.

In other words, the invoicing system would reconcile the metric qty against the Product qty and then bill the overage used over the qty previously paid for.

Is this at all possible within the standard install or am I barking at custom modification.

I've tried to find a clear answer elsewhere and cannot.

 

Thanks

Daniel