On a per cell basis, the contents need to be arranged alphanumerically and then continuous ones need to be grouped into <first term>-<last term> and all comma-space seperated.
C3506, C3508-C3511, C3536-C3539, C4120, C4121, C4620, C4621,
Rules: Non-continuous remain so, 2 continuous remain so and 3+ continuous are grouped. The cells may come comma-no-space or comma-space and need to be sorted into comma-space.
And a check for duplicates in all cells would be a great bonus!
I've attached a dataset.