Using worksheet functions to calculate a column letter is not really a good plan. Using Peter Albert's VBA method is a much better way to do this!
I had the desire to do one, using the functions of the worksheet, just for fun: /
A-ZZ
=IF(A1<27,CHAR(64+A1),IF(A1<703,CHAR(64+INT(A1/26))&CHAR(A1-INT(A1/26)+64),"TOO BIG!"))
A-XFD (not working)
=IF(A1<27,CHAR(64+A1),IF(A1<703,CHAR(64+INT(A1/26))&CHAR(A1-(INT(A1/26)*26)+64),CHAR(64+INT(A1/676))&CHAR(64+(INT(A1-(INT(A1/676)*676))/26))&CHAR(64+INT(A1-((INT(A1-(INT(A1/676)*676))/26)*26)))))
The final will fall on trying to work out the 3rd character in the address, I just can not worry, because using it is not very good!
Nickslash
source share