Yes, if you're on Exchange server. Use the rules in the Out of Office Assistant (Tools menu). These will run from the server so long as you have out of office turned on.
If you have to use the Rules Wizard (no Exchange Server), it can be a little tricky to make sure you aren't overinclusive. (Unless you really trust your manager. <img src=/S/grin.gif border=0 alt=grin width=15 height=15> ) Also, when using the Rules Wizard, you need to leave your connection open and Outlook running in order to process and forward the mail in real time. Otherwise, they'll all get sent when you get back and start up Outlook next week.