Not sure why admin would fail for the c$, unless file and print shareing where turned off...as for the 98 boxes at the command line you can do NET USE [devicename | *] [\\computername\sharename[\volume] [password | *]]
[/USER:[domainname\]username]

the domain name is optional, i am assumeing you dont have a domain.

the other option would be to get a cheap nt4 server box or 2k in pdc mode and have every one jon a domain.