I know this isn't the best backup utility but it is all I have to work with right now...

I have a drive mapping to the admin share (ie c$) on another server that I want to backup. When I am logged on and run ntbackup it works fine. When I schedule it to run while I am logged off it can't see the drive mapping and says nothing to back up. This makes sense, however, I need to be able to backup these remote drives while logged off. Any ideas other than get some real backup?