PAYING FOR UPGRADES

Hello Folks of the Forum. As I work in the travel industry, I am fortunate enough to purchase discounted seats through Touchdown (I believe they are N class). Question, if I want to upgrade to PE using my miles, is it possible to pay the difference between the published N class fare and M class fare (which I believe is the minimum on which I can upgrade), then use my miles?
In other words, if I want to upgrade using miles, can I still do it using my discounted seats, or do I have to purchase an M class in the first place....phew!!!
Many thanks, [^]
In other words, if I want to upgrade using miles, can I still do it using my discounted seats, or do I have to purchase an M class in the first place....phew!!!
Many thanks, [^]