MakeIndex, Nomenclature, Glossaries and Acronyms ⇒ Indexing names in footenotes

[Jongomez]

I am using in the preamble:
\usepackage{imakeidx}
\makeindex

And within the document (at the end):
\clearpage
\index{Índice alfabético}

\addcontentsline{toc}{chapter}{Index }
\printindex
\end{document}
************************************
For names in the main document I write (example): text, text, tex......\index{Einstein} Einstein ....
and I get the correct entry in the Index page:

Einstein, 10 (page no. 10)

BUT, for names within a \footenote I wish the letter f to appear (in italic) the Index page, after the page number, i.e.

Einstein, 35f (f in italic)

Can you help me?
Thanks a lot,
Jon A. Gomez