rate cards and billing rules.

I am interested in how others have worked with creating duplicate rate cards for clients. Say, for example that I want to have a management accounting report that charges an extra 5% for each hour on a timesheet above the rate card because the service provided to that specific client uses more overhead costs because of the nature of the work. However, I am not going to charge that additional 5%. It is only for management reporting purposes. So I went to run the transactions through twice, sort of. Once for the actual booking of worked time and a second