Numbering grid cells using ABC & 123 in QGIS

Question

I'm trying to number a grid from 120 rows by 120 columns: horizontal ABC, vertical 123 using Algorithm ID: 'native:creategrid' and Algorithm ID: 'QgisregularPoint'.

Numbering vertically isn't a problem. Numbering horizontally using is. Numbers should become characters.

I use:

char(65 + ("hor"%26)) || char(65 + round("hor"/26, 0))

thinking that if "hor" == 13, the result should be NA but it gives me NB.

I cannot find out what I am doing wrong. Take a look at the table:

Answer 1

Instead of round() use the floor() function:

char(65 + ("hor"%26)) || char(65 + floor("hor"/26))

It will always round down the result, which is what you want in your case.