The database file which stores the SMS & call-log info is stored here:
/home/user/.rtcom-eventlogger/el.db

If you run it through the strings command on your GNU/Linux desktop (not sure if strings is available for maemo5), you'll see that it starts with "SQLite format 3". I assume you can use any SQLite client to read the database. Shouldn't be too hard to write something which can export/import into the database, assuming it's self-contained.