Drop folder put in category

Is it possible to add content from a drop folder into a specific category?

Are you putting there the content itself or an mrss xml?
I think you can do with the xml

as content.
what should I write in the xml?

You can see here:
http://www.kaltura.com/api_v3/xsdDoc/?type=dropFolderXmlBulkUpload.dropFolderXml