Well I've managed to get the shortcut into Outlook - I was trying to add it to the folder list and not the outlook bar.
I guess I still need to add access permissions because when I click on someone elses calendar I get the following message:
"Unable to display the folder. Microsoft Outlook could not access the specified folder location. Could not open the item. Try again."
I orginally thought this might be because some peoples docs are on different drives but I tried it with someone whose docs are the same drive as me and I get the same problem. Maybe the part of saving as a system file has something to do with it?