How to change the meeting room resource up to one year in exchange 2007

hi,

We have Exchange 2007 and Outlook 2007 - I have users who would like to book resources (meeting rooms) for a whole year. However when they try to do so the resource rejects meeting: 

Your meeting request was declined.

The end date of this series of recurring meetings is too far in the future. This resource can only be scheduled up to 180 days in advance. 

Can I change the default property on the resource to a higher value - and if so - how? 

please provide me the GUI way  and shell command. 

Thankyou