HtmlDocument.ExecCommand(string, bool, object) exposes a large array of commands for which there are no methods exposed on System.Windows.Forms.HtmlDocument. Using HtmlDocument.ExecCommand(string, bool, object) you can insert new HTML elements, select and format text, and clear any cached authentication credentials. For a full list of commands, see tp://go.microsoft.com/fwlink/?LinkId=198814.
Certain commands, such as copy, have return values. In the current implementation of HtmlDocument.ExecCommand(string, bool, object), you cannot obtain a return value from your call. To retrieve return values, use the corresponding unmanaged method on a HtmlDocument.DomDocument reference instead.