Word count on update

We need to count the words in an update, inside a subitem. We can count the words of a text column with a formula column but not those in a certain update. If there was a rich text column, so that you could write formatted text like in an update, we could write in that column instead of the update section, and then count the words there. As there is no rich text column (yet) we have to use the update section. But then again, how could we count the words in a certain update, say a pinned one… Thanks for any ideas.