Newbie: Can users change their own CVS password?

[HeyYou!]

I was saddle with CVS administration, so please excuse my simple
questions.  I cannot find the answers in the documentation.

When users try to change their own password using passwd they get a
message that passwd is not ussported on the server.  I know that I have
seen users cahnge their password from their PCs using a dialog box.
Any suggestions on what be used to let non-root users change their own
password?  We are using WinCVS and Tortoise.
Thanks in advance!
Caveman