I haven't counted the number of columns, but the limitation of A through IV
is rather short-sighted.

Of course the number of rows of 65,536 seems sufficient. Just the
disparaging difference between the number of columns versus the number of of
rows seems to limit the function because the user has to modify the
application (what I'm using it for) to conform to the limitations of the
program.

This is just a complaint, nothing more.