replace the 4th letter from the right

[ExcelPeon]

I have a large set of data that contains SKUs with different number of characters. Each SKU can range from 10-20 characters. The only thing that is constant is the last 4 characters. Which formula can i use to only replace the 4th character from the right?

Example
SKU1-U-101
SKUUU-U-101

replace "U" with "A"

Results
SKU1-A-101
SKUUU-A-101

Thanks in advance!

 

[sandy666]

What if i wanted to increase the letter by one to get to the next letter?

you need to define representative examples and real needs not what-if
there should be a pattern not randomly choosen letters or positions

basic text can be extracted before second delimiter from the end
then
in extracted text after that delimiter you can replace letter by letter, all A to B, all B to C and all U to X
there will be a little problem in bolded text because A to B then B to C will be as A to C on the end

@Michael M : post#2

 

[Michael M]

@sandy666
Sorry, saw the power query response, but didn't see the formula.....

 

[sandy666]

@Michael M
no problem, I was a bit confused