OK fattade. Detta hjälpte:http://docs.mongodb.org/manual/reference/connection-string/
mongoimport --host meteor.m0.mongolayer.com --port 27017 --username client --password e63aaade-xxxx-yyyy-93e4-de0c1b80416f --db kanjifinder_meteor_com --collection kanji --type csv --file c:\kanjifinder\kanjifinder.csv --headerline