Persistent logins from mapped drives

I am running a mix of 98/2000/XP machines, and they are all
connecting to samba servers in each branch office. Since
the NT5x boxes dont support network logon the same way that
win98 does in regards to authenticating samba, we're forced
to create a shortcut to the login script in the startup menu.

Problem:

Windows NT5x has a "/persistent" option you can add to the
login script, which forces windows to forget the mapped
drive each time the user logs off. Win98 does not support
this. Is there an equivalent switch?

Thanks in advance,
Ian Wills, MCP A+