Calender sharing to group

[xenophobia]

Hi,
Im using ZCS 5.0. I had a situation here. I created a resource account called:
resource1@localdomain.com

This resources is shared to all the users under @localdomain.com.
Whenever a user allocate this resource, the resource's calendar will shows there is an allocation for the selected time. Just like you allocate your meeting time.

I wanted to share this calendar to all the users so that they know until when this resource is free. My problem is, I have 100 users, it is kinda stupid to add the 100users 1 by 1 into the sharing list.

Is there a way for me to share all the user in a group or something? Based on domain? *@localdomain.com
So that in future, if there is a new user called newguy@localdomain.com created, automatically the calendar will be share to him.