WithinVBA if you have a method to identify the specific entry then you can set anything (within reason) you like. For example when creating automation of outlook appointments I save the entryid for the item and then I use that unique entry to control edits to my calendar.
Alternatives are ordinary fields such as the subject ... but it would have to be unique and unchanging hence I record the entryid.
I feel we may not have got to the crux of your request though so by all means clarify as necessary.
Chris
