procedure TForm1.StringGrid1KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
var
   i,j,LeftCell,TopCell : Integer;
   BottomCell, RightCell : Integer;
   TextBuf : String;
   SysClip : TClipBoard;
begin
   SysClip := TClipBoard.Create;
   //trap the Control-C or Control-c keys
   if (Shift = [ssCtrl]) and ((Key = 67) or (Key = 99)) then begin
      //get the coordinates of the selected region of the grid
      LeftCell := StringGrid1.Selection.Left;
      TopCell := StringGrid1.Selection.Top;
      BottomCell := StringGrid1.Selection.Bottom;
      RightCell := StringGrid1.Selection.Right;
      //The variable TextBuf is used to hold the information that will to to the clipboard
      TextBuf := '';
      //for all of the selected cells, copy the contents to
      //TextBuf and separate lines by returns and cells by tabs
      for i := TopCell to BottomCell do begin
         for j := LeftCell to RightCell do begin
            if j = LeftCell then
               TextBuf := TextBuf + StringGrid1.Cells[j,i]
            else
               TextBuf := TextBuf + #09 + StringGrid1.Cells[j,i];
         end;
         TextBuf := TextBuf + #13#10;
      end;
      //Now move the contents of TextBuf to the windows clipboard
      SysClip.AsText := TextBuf;
      //destroy the clipboard object , this does not affect
      //the contents in the Windows clipboard
      SysClip.Destroy;
   end;
end;

Submitted by: Tom W Khoury