There is not such a thing, probably because, as has been explained before, nobody can agree on what a "column" is, bytes, code points, glyphs, pixels? The Scintilla definition used for the status bar is "code points, except for tabs. which can be multiple columns to reach a multiple of the tab width".

But that may not match the definition of "column" from another tool, so its only useful for ASCII or non-combining characters Unicode, and then only when the width of tabs is also agreed.