Can VB.Net check network user inforamtion, if net is down

Question… Can VB.Net check network user name and password information if the
network is down. I know a user can log into a local machine (PC) if the
network is down, using cached network user information on a local machine.
The user simply logs into the ‘stand-a-lone’ computer using their network
user name/password. However, can .NET system,security access the local
machine’s cached information that has the network security information?
Basically, I need to reproduce the network user’s login for a local machine,
when the network is down, and apply this to an application.

Thanks..