As per page 1189 of the 12.5 admin guide mentions particular target types .
DLP versions :- 11.x , 12.x , 14.x
Step 1 :- created an access database in MS Access
Step 2:- Created a network share and placed the file in it
Step 3:- Created a keyword policy
Step 4:- Created a file system target scan for MS access
Mentioned the shared path as highlighted below
Entered the Credentials for the Shared path
Step 5:- Created incidents