Libro.Cells[1,1]:=UnDataset.FieldByName('NombreDeUnCampo').AsString;
Libro.Range['A1', 'E'+inttostr(UnNumero)].Merge;
Libro.Range['A1', 'E'+inttostr(UnNumero)].Borders[xlBottom].weight := -4138;
Libro.Range['A'+inttostr(i+1), 'E'+inttostr(i+1)].Merge;
Libro.Range['A1', 'E'+inttostr(UnNumero)].Borders[xlTop].weight := -4138;