'In' or 'On'

[glenvern]

I am writing a sentiment inside a book and not sure which of the above to use-

the sentence goes - to commemorate your success 'On' or 'In' your 'Masters' degree course.

or should I use 'in the'.?

to commemorate your success in the 'Masters' degree course.

[Tdol]

I'd say 'in your'.

[Kas55]

I would agree with 'in'' in this instance.

'On' would be used if you said, "Congratulations ON achieving your Master's degree". However, you are wishing the person for achieving success IN a course.

Hope this is of help to you.