ryoku
You are searching for a Single Word?
Have a look here:
ftp://ftp.support.veritas.com/pub/support/products/Exchange_Mailbox_Archiving_Unit/293428.pdf
On Page 17, Indexing Level.
If set to Medium, you should be able to search for "Single word search of metadata, body and attachments"
I think it's time to open a case @ SYMC.
Cheers