Right, here is a regexp for valid formats: 
/^[A-Z]+[0-9]*[A-Z]*/;

[download]
N1234Z becomes N12350
N12359 becomes N1235A
N9999Z becomes NA0000

Ordering of the addition is less important than testing all possible variations. Technically NA0000 is invalid since it has a number, but the number part equals zero. I can handle that logic outside of this code construct.

In reply to Re^2: Increment a mixed alphanumeric (Updated) by miketosh
in thread Increment a mixed alphanumeric by miketosh

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