c# .net dll

I need a .net dll developed. This dll will provide an interface (winforms form) with the following controls: Treeview on the left, grid on the right. The treeview will contain root nodes that are sharepoint sites. When the node is clicked, the treeview is populated with the document libraries and lists ect. On the right of the treeview would be a grid displaying files or list items. I need the ability to save to and pull from sharepoint specific files. authentication will be either ntlm or basic.