Hello @ptrentham ...
If you re-enroll the student in your Honors course, the grades for that student should re-appear back in your "Grades" page so that you could export that data to an Excel *.csv file. Just make sure to drop the student from the Honors course once you are done so that he/she doesn't have access to both courses...if that is what is intended. If you are not able to re-enroll the student in the Honors course, you will need to speak with your school's Canvas administrator to take care of this for you.
I hope this helps a bit. Sing out if you have any questions...thanks!