Save your keywords/phrases to a text file, putting each keyword/phrase on a new line, e.g.

Then refer to that file in the File name field, prefixing the file name with an '=', e.g.

When you run the search the keywords will be loaded from the file and used to search the specified location.
Important: If you're having problems making this work check that the File List functionality has been switched on in the Configuration->Advanced->File List Settings.