J3.9.16 & F2C 6.17.4

Hi,
I've made a F2C plugin which, when an article is saved, create a new directory (with the alias of the article as name) in the images directory.
It's ok but I would like to display a link to this directory in the backend article form (when the article is saved, of course).
Since the backend form is not overridable cleanly, the easiest way would be to use a kind of "info" content type field.
But the text of the info type field is not stored in a db fieldcontent with a link to the article formid.

Well, do you think of an easy way to do this?

Regards
Marc