In case it's useful to anyone, here's what I've just used to export data from the Journal to an Excel spreadsheet (csv file). Run this query using phpmyadmin or similar. Adjust the fields as desired. The j.course is the id for the course (pull it from the url: http://moodle.<somewhere>.ca/course/view.php?id=493)
SELECT journal journalid, j.name, j.intro, j.days, FROM_UNIXTIME(j.timemodified) journallastmodified, u.firstname, u.lastname, u.email, FROM_UNIXTIME(modified) usermodified, text, rating, entrycomment, teacher, FROM_UNIXTIME(timemarked) timemarked, mailed FROM mdl_journal_entries je
INNER JOIN mdl_journal j ON j.id=je.journal
INNER JOIN mdl_user u ON u.id=je.userid
ORDER BY journal, modified
Be sure to tell phpmyadmin to export as "CSV for MS Excel" and put a check in the field "Put fields names at first row".