как получить элемент?

using System;
using System.Runtime.InteropServices;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using AcRx = Autodesk.AutoCAD.Runtime;
using AcEd = Autodesk.AutoCAD.EditorInput;
using AcDb = Autodesk.AutoCAD.DatabaseServices;
using AcAp = Autodesk.AutoCAD.ApplicationServices;
[assembly: CommandClass(typeof(Rivilis.EntFunctions))]
namespace Rivilis
{
  public class EntFunctions
  {
    [System.Security.SuppressUnmanagedCodeSecurity]
    [DllImport("acdb17.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "?acdbGetAdsName@@YA?AW4ErrorStatus@Acad@@AAY01JVAcDbObjectId@@@Z")]
    private static extern int acdbGetAdsName(long[] name, ObjectId objId);
    [DllImport("acad.exe", CallingConvention = CallingConvention.Cdecl, EntryPoint = "acdbEntGet")]
    private static extern System.IntPtr acdbEntGet(long[] name);
    [DllImport("acad.exe", CallingConvention = CallingConvention.Cdecl, EntryPoint = "acdbEntMod")]
    private static extern System.Int32 acdbEntMod(System.IntPtr resbuf);
    [DllImport("acad.exe", CallingConvention = CallingConvention.Cdecl, EntryPoint = "acdbEntMake")]
    private static extern System.Int32 acdbEntMake(System.IntPtr resbuf);
    [CommandMethod("DXFGet")]
    static public void DXFGet()
    {
      AcEd.Editor ed = AcAp.Application.DocumentManager.MdiActiveDocument.Editor;
      AcEd.PromptEntityOptions entityOpts = new AcEd.PromptEntityOptions("\nSelect entity: ");
      AcEd.PromptEntityResult rc = ed.GetEntity(entityOpts);
      if (rc.Status == AcEd.PromptStatus.OK)
      {
        long[] ent = new long[] { 0, 0 };
        acdbGetAdsName(ent, rc.ObjectId);
        System.IntPtr rb = acdbEntGet(ent);
        AcDb.ResultBuffer dxflist = AcRx.DisposableWrapper.Create(typeof(AcDb.ResultBuffer), rb, true) as AcDb.ResultBuffer;
        if (dxflist != null)
        {
          foreach (TypedValue val in dxflist)
          {
            ed.WriteMessage("\n({0} . {1})", val.TypeCode, val.Value.ToString());
          }
        }
      }
    }
    [CommandMethod("DXFDup")]
    static public void DXFDup()
    {
      AcEd.Editor ed = AcAp.Application.DocumentManager.MdiActiveDocument.Editor;
      AcEd.PromptEntityOptions entityOpts = new AcEd.PromptEntityOptions("\nSelect entity: ");
      AcEd.PromptEntityResult rc = ed.GetEntity(entityOpts);
      if (rc.Status == AcEd.PromptStatus.OK)
      {
        long[] ent = new long[] { 0, 0 };
        acdbGetAdsName(ent, rc.ObjectId);
        System.IntPtr rb = acdbEntGet(ent);
        AcDb.ResultBuffer dxflist = AcRx.DisposableWrapper.Create(typeof(AcDb.ResultBuffer), rb, true) as AcDb.ResultBuffer;
        acdbEntMake(dxflist.UnmanagedObject); // Duplicate entity
      }
    }
  }
}