Old Technique

CopyFileOverwrite[f1_,
  f2_] := (If[FileExistsQ[f2], DeleteFile[f2], False];
  CopyFile[f1, f2];)
NewRun[s_] := (str =
   OpenWrite[FileNameJoin[{$TemporaryDirectory, "temp.bat"}]];
  WriteString[str, s];
  Import["!" <> Close[str], "Text"];)

WriteToClipboard[type_,
  data_] := (CopyFileOverwrite[
   FileNameJoin[{$InstallationDirectory, "SystemFiles", "Links",
         "NETLink", "Wolfram.NETLink.dll"}],
       FileNameJoin[{$TemporaryDirectory, "Wolfram.NETLink.dll"}]];
      csfile = FileNameJoin[{$TemporaryDirectory, "File.cs"}];
      exefile = FileNameJoin[{$TemporaryDirectory, "File.exe"}];
  file = OpenWrite[csfile];
  WriteString[file, "using System;
      using Wolfram.NETLink;
      using System.IO;
      using System.Drawing;
      using System.Windows.Forms;

      public class File{
       [STAThread]
       public static void Main(String[] args) {
          string input = System.Console.In.ReadToEnd();
          byte[] bytes = Convert.FromBase64String(input);
          Stream stream = new MemoryStream(bytes);
          IDataObject dataObject = new DataObject();
          dataObject.SetData(args[0], stream);
          Clipboard.SetDataObject(dataObject, true);
        }
      }"];
  Close[file];
  Import["!C:\\Windows\\Microsoft.NET\\Framework\\v4.0.30319\\csc.exe \
 /reference:Wolfram.NETLink.dll " <> csfile, "Text"];
  dataloc = FileNameJoin[{$TemporaryDirectory, "data.txt"}];
  datafile = OpenWrite[dataloc];
  WriteString[datafile, data];
  Close[datafile];
  NewRun["type " <> dataloc <> " | " <> exefile <> " " <> type];)