Thanks for the replies.
- I Tried out EasyGPS - it doesn't have import capabilities.
- ExpertGPS does, but it had problems converting the CSV file, and did not recognise the Lat/Long fields. Maybe the CSV fields are not in the right order?
- I couldn't find GeoBuddy.
- GPSU say that I can import direct from MapSource and then download to the Meridian. I haven't tried it yet.