I know that there is a concept of CSV lookup and external lookup and all, but those will create a new field and set a value if the value matches with those in watchlist. What is i need a new field creation and set a value if a partial match with watchlist happens. Can we use regex ?. Also is it possible to edit the file that is already added from the console itself.?
Have you tried the getwatchlist app?
https://splunkbase.splunk.com/app/635/