Share a single phonebook for multiple networked computers

I am working for a telecoms company that uses modems to dial in to
their customers systems for admin purposes. At the moment, there are
many dial up connections (~200 or so), but they don't all exist in a
single place. Some are duplicated on all the computers, others are not.
Ideally, there would only be one resource where new connection details
are added, and would immediately become available on everyone's
computer.

The most logical method seems to be a single .pbk file saved on the
server with the connection details stored on there. I've experimented
with various methods but I don't seem to be able to save a password and
username so anyone can access this. This seems to be the default
procedure for XP as a security measure, but even if I opt for the
password to be available for everyone, it still will not save it for
someone accessing over the network. There would have to be a large
database of un/pw to accompany the phonebook file, which seems to
defeat the point.

The other option is using Rasdial scripts, which are considerably less
user friendly. They also don't allow for any variation with hardware
and port attachments, which a phonebook file would.

Can anyone advise a method of sharing a large number of dial up
connections between multiple users keeping logon information intact?