What you need to determine is whether you want the person getting the link to open it in a Notes client or in a web browser. If you want them to open it in a Notes client, see my comment earlier
(specifically the part about Notes URLs, but any of it is valid). If you want them to open it in a web browser, you just need to send a link with the format http://www.myserver.com/mydb.nsf/myview/mydoc?OpenDocument
where the myview
value could be a view name (URL encoded), a view universal id or a 0, and your mydoc
value could be a key that matches the first sorted column or the document universal id.