Drag and Drop из RichEdit

 var
   Form1: TForm1;
   richcopy: string;
   transfering: boolean;
 implementation

 {$R *.DFM\}

 procedure TForm1.RichEdit1MouseDown(Sender: TObject; Button: TMouseButton;
   Shift: TShiftState; X, Y: Integer);
 begin
  if length(richedit1.seltext)>0 then begin
   richcopy:=richedit1.seltext;
   transfering:=true;
  end; //seltext
 end;

 procedure TForm1.ListBox1MouseMove(Sender: TObject; Shift: TShiftState; X,
   Y: Integer);
 begin
  if transfering then begin
   transfering:=false;
   listbox1.items.add(richcopy);
  end; //transfering
 end;