MID function not working properly

So I created a concat formula to return column names all the way to "ZZ"; however, it's returning incorrect values for the second letter after "ai" and I can't seem to figure out why. The piece of formula misbehaving is the following (it has been simplified for convenience, but it works the same... or rather doesn't):

=(MID("abcdefghijklmnopqrstuvwxyz",(38/26-(QUOTIENT(38-1,26)))*26,1))

The result of start_num's argument is, of course, 12 (the 38 is AL's column number); HOWEVER, the letter given by MID is actually "k" (11th character), not "l", and short of actually sticking a "12" there, I haven't been able to make it work.


This is one of those "optimization" experiments that ends up taking so much more time than just doing everything the "slow and inconvenient way"...