Function to get the column name of a cell?

edit

Hello,

=REGEX(ADDRESS(ROW(),COLUMN(),4),"(.+)(\d+)","$1") should work

Update According to @keme's comment (thanks for that)

=REGEX(ADDRESS(ROW(),COLUMN(),4),"([:alpha:])(\d+)","$1") --or--
=REGEX(ADDRESS(1,COLUMN(),4),"([:alpha:])(\d+)","$1")

But anyway - solution using SUBSTITUTE() and taking into account that row isn't important at all is much simpler.

Hope that helps