we have a situation where our old user account's format have changed and instructors may have inadvertently assigned grades to them by mistake.
In the old format, their login account was something like acu123456 and the new format is just the numbers - 123456
so when say John Smith logs in as 123456, there are now 2 john smiths... when the instructor enrols them to their course, they added both of them by mistake.
Ho do I find out which accounts have NOT BEEN assigned grades for users whose account is in the old format (ie. acuXXXXXX).