Wow.. Thanks for that.
I was looking at the OScommerce database, and it looks like I need to do a lot to get this stuff imported to the correct tables.
It looks like the tables: categories, categories_description, products_description, products_to_categories are the needed tables.
(with a lot of rows in the tables :-/ )
I'm new to OScommerce, and as the OScommerce forum was down (it's working now again) I did not find an easy way to import a file like this..
Going over to the forum now to "maybe" find a tool to do this the easy way.