[Exim] Web Browser interface

I've got Exim running on a Solaris box, with a Web mail interface running on a
NT server for users to access their email remotely via a web browser.

I'm looking for a convenient way to allow users to change their passwords on
the Solaris/Unix server, and to create their own email forwarding and holiday
'away' bounce-back auto-reply messages.

The constraints I am under are:
1) Jave/CGI not to be run on the Solaris server.
2) Live telnet command-line not to be given to users.

Any ideas? or is this a mission impossible?

Thanks.