Here's a modified
small part of the script you are referring to in the Tech Database... try inserting it into the script you are playing with and see if it helps.
Basically, I think you need to create a "recipient" object first - ie. the shared calendar's owner name and then set the Calendar and Item objects to that object's shared folder before you try accessing any other properties.
Change "Training Room Bookings" to whatever the shared calendar you are after is called.
/// SNIP/// - only part of the larger script
olPrivate = 2
olFolderCalendar = 9
objOutlook = ObjectOpen("Outlook.Application")
objMAPI = objOutlook.GetNameSpace("MAPI")
;objCalendar = objMAPI.GetDefaultFolder(olFolderCalendar)
;objItems = objCalendar.Items
;objCurrent = objMAPI.CurrentUser
objCurrent = objMAPI.CreateRecipient("Training Room Bookings")
objCalendar = objMAPI.GetSharedDefaultFolder(objCurrent, olFolderCalendar)
objItems = objCalendar.Items
objName = objCurrent.Name
message("",objName)
;objName = "Joe Shmoe"
/// SNIP/// only part of the larger script referenced in the Tech Database