type
 TGridCracker = class(TStringGrid);

 {...}

 implementation

 {...}

 procedure SetCaretPosition(Grid: TStringGrid; col, row, x_pos: Integer);
 begin
 Grid.Col := Col;
 Grid.Row := Row;
 with TGridCracker(Grid) do
 InplaceEditor.SelStart := x_pos;
 end;

function GetCaretPosition(Grid: TStringGrid): Integer;
 begin
 with TGridCracker(Grid) do
 Result := InplaceEditor.SelStart;
 end;



//Пример

procedure TForm1.Button1Click(Sender: TObject);
 begin
 StringGrid1.SetFocus;
 SetCaretPosition(StringGrid1, 1, 3, 5);
 end;