Hi,
This is described in our documentation. Please see: http://kentico.com/docs/devguide/creating_documents.htm. You need to change this example so that it works for your site. For example
TreeNode node = new TreeNode("cms.news", provider);
you will change to
TreeNode node = new TreeNode("cms.folder", provider);
To copy files from your shared folder on a disc you need to do similar process - you will create cms.file documents under your cms.folder. Then you assign properties to these files.
Best regards,
Vita Janecek