Hi
I am not familiar with these modules. Please look at this module and try this one.

http://search.cpan.org/~corion/WWW-Mechanize-Shell-0.34/lib/WWW/Mechan
+ize/Shell.pm
[download]

This could also help

http://httpd.apache.org/docs/howto/auth.html#basicworks
[download]

This can help you.
Thanks
Sasi Kumar