On windows 95/98, I use a batch file to run the "net use" that can be called from either the Registry or the startup. Or if you have zenworks, you can force run a nal to run the batch file.
As long as the username matches, if you set the password on the windows box that you are trying to map to so that it never expires (I know good admin security), you can add the password to the end of the net use statement.