My requirement is to uniquely identify any excel workbook across the network,
which leads me to a requirement of tagging the document.

Possible solutions a-
1. using filename (not useful, since it can be changed)
2. using path (not useful, since file could be copied or moved)
3. using documentProperties (This solves my prob to a large extent, first it
is persistent and associated with the workbook. The only problem is that
users could see the DocumentProperty in custom tab and change the value.)

Is there any way to hide the Documentproperty or another feasible way to tag
an excel workbook.

Thanks,
Rahul