Hi Mia,
In the grade set, you should be able to give a grade a description - the column in the middle.
Staff will then enter a number onto the marksheets instead of the whole description.
Then when you go to your assessment manager report or profile, you can bring it through as a field - don't go for Grade, but Grade Description. This should pull it through onto your report.
If you need any help give me a shout.