I do not use the NMC reports a lot - i guess, most of us just ignore them. But if you click the Reports icon, look at the NetWorker Backup Statistic folder. Here you find the Save Set Details by Client report which might help you. From here, the use is similar to NW's Save Set query and you should be able to get along easily.
Do not forget that your success depends on the size of the NMC database (adjustable) and the number of backups you have run in the interim - your info might have already been deleted.