'Grouping' when some entries have suffix

I am trying to sort student ID's into classes based on dates as a naming convention. The convention is 'last two of year', 'day', 'month', 'serial number', 'evening class?'

So for instance I would have these students in a class:

26010101 (Student 1 in class starting 1/1/2026)

26010102 (Student 2 in class starting 1/1/2026)

26010101N (Student 1 in NIGHT class starting 1/1/2026)

26010102N (Student 2 in NIGHT class starting 1/1/2026)

(Okay, it isn't the best naming convention, but I started this in 2009, so it's too late to change now.)

I need to sort them into classes, so I need them to read: 26010101, 26010102, 26010103, 26010101N, 26010102N, etc. No matter how I try to extract and sort, I keep getting 26010101, 26010101N, 26010102, 26010102N.

I'm sure there is a way to do it, I'm just not finding it. TIA