I am trying to do something that I am sure is very simple to achieve, but it
is beyond my limited knowledge i.e.

I have a list of 100 3 digit codes that can be alpha/numeric.

Each code represents the aggregate of of another series of 3 digit codes
that can also be alpha/numeric e.g.

Parent Y01 is total of children codes in ranges 111 - 120, AAA-AAE
Parent Y02 is total of children codes in ranges 100-110, 131-140, ABB-ABF
Parent Y03 is total of children codes in ranges 121-130, 141-150, AAF-ABA

I would like a formula that will return which parent code applies for any
given child code i.e.

Input: Child code = 111
Output: Parent code = Y01

Can anyone suggest a solution?

cangiff