Seems fitting and probably should have been predictable – for a believer in the Iron Law of Irony – that an application meant to facilitate blogging, in this case by making aggregation of interesting material an easy “few clicks” operation, would annihilate my blogging. Anyway, is what happened.
At the point in the post where you want the number-link to appear, type a space then opening double parentheses. Place the text you wish to appear in the footnote after the double parentheses. Close the footnote with closing double parentheses.