Hi,
Unlike SendStringToExecute() or SendCommand() which requires a string as argument, EditorCommand() method is quite similar to the command LISP function, it accepts typed arguments (string, int, double, Point3d, ObjectId, SelectionSet...)
If you want to use SendCommand(), you can acces to COM without referencing the COM libraries by using the dynamic type (late binding)
dynamic acadApp = Autodesk.AutoCAD.ApplicationServices.Application.AcadApplication;
var thisDrawing = acadApp.ActiveDocument;
thisDrawing.SendCommand(...);
But with plain .NET you can call LISP function using the Application.Invoke() method.