The LaTeX Beamer Class

Hello, beamer-users,

I use a lot Beamer, with pdflatex, usually with the 'Madrid' theme.

Does anybody know how to get the presentation page number on the summary page 
(\titlepage) ?

Say, instead of having:
1 - part1 title
2 - part2 title
3 - part3 title

how to get:
1 - part1 title                3
2 - part2 title               12
3 - part3 title               34

with the numbers being of course the frames page number (not the pdf file page numbers!)
This would be particularly useful for handouts, as students easily get lost when 
handouts have numerous pages.

Thanks,