Outlook 2003 Shared Calendar for Group Vacation Schedules?

We are using Outlook 2003 with Exchange Server 2003. We have a shared calendar that we would like to use for a vacation schedule for 40 employees or so. We would like to send the vacation request to one person to approve or decline “like a meeing request” and then have it add itself to the Shared calendar and the requestors calendar.

Does anyone have any ideas?

Thanks