How can I mark a refunded order as fulfilled?

I have an order that needs a partial credit but NOT to be fulfilled. Is it possible to fulfill the order, process the credit then unfulfill the order so we can process it normally? We typically run 5-6 weeks before we fulfill an order. I usually ask customers to wait until their order ships before I can process any credit. Not a good business practice. If I fulfill it now ( 5 weeks to early), I run the risk of thinking it is completed.

Would this be a workaround?

Thanks so much!