It needs to be a resource. Set up the resource like a normal user. Then go to:
Tools
OPtions
Preferences Tab
Calendar Options
Click the Resource Scheduling button
Select the first two check boxes - Auto accept... and Auto decline conflicting meeting requests
Click the Set Permissions Button
Go to the Permissions tab
Under Name select default
Below that where you can select the permissions level select Author
That is all there is to setting it up...Now.....
When you get ready to book a meeting invite the resource but make sure you put it in the Resource field and not the required field or it won't work.