The MeetingWorkspaceUrl element contains the URL for the meeting workspace that is included in the calendar item. A meeting workspace is a shared Web site for planning the meeting and tracking the results.
The MeetingWorkspaceUrl property is read-writable for the organizer's calendar item. It is read-only for meeting requests and for attendees' calendar items.
The schema that describes this element is located in the EWS virtual directory of the computer that is running MicrosoftExchange Server 2007 that has the Client Access server role installed.