In version 9 when you export custom reports it will ask for a file name. All the files for the export are then contained within that one zip file instead of lots of individual files like prior versions.
BTW, one of the design goals for version 9 was removing all the processes that were hardcoded to the a: or b: drives like exporting custom reports, posting contributions to a disk file, etc.
It's all good now. I exported the report from an old backup, backed up the current file, deleted the reports, corrected the table, imported the custom report, ran it, renamed it and closed the software.