To make a long story short: WP All Import does the trick. If you’re looking for a plugin, which is useful to import, update and even delete (custom) posts by a – if necessary or reasonable – filtered list of records, you’ll need the pro version, but you get a lot of bang for the bucks. Useful for synchronizing information with an erp-system or a related database. Thanks to John for insisting, even though his suggestion was too sophisticated for my skills 😉
