Individual cash memo through VF04 in the background

We have an existing process in cash sales order where PGI also happens immediately. Our requirement is to schedule background job through VF04 periodically, say every 15 minutes. The issue is that it does collective billing for all the sales orders created within those 15 minutes. I need it to create individual cash memo for every sales order. On the other hand, when cash memo is created manually in other locations, collective billing is to be allowed. Hence I cannot change routine in copy control to 003. Please advise.