Filter - Stringrid - Delphi

procedure Filter(ACol: Integer; Exp: String);
var
  I,Counter:Integer;
begin
FilterList:=TStringList.Create;
  With StringGrid1 do
  begin
    //Filterliste mit Gridinhalt füllen
    For I := FixedRows To RowCount - 1 Do
      FilterList.Add(Rows[I].Text);

    //Grid filtern
    Counter:=FixedRows;
    For I := FixedRows To RowCount - 1 Do
    Begin
      If Cells[ACol,I] <> Exp Then
      Begin
         Rows[I].Clear;
      end
      Else
      begin
         If Counter <> I Then
         Begin
           Rows[Counter].Assign(Rows[I]);
           Rows[I].Clear;
         End;
         Inc(Counter);
      End;
    End;
    RowCount:=Counter;
  End;
end;