I thought this would work, but it doesn't. =countif(a1:a5,"*#*")
To demonstrate, put 999999 into a1 through a5 then make the column 1 character wide.
I have a workaround that uses vba, but it is very slow. It uses .cells.find (what:="#") and loops through the selected range.
I would much prefer an solution that uses an excel worksheet function.