Rename stored procedure columns Informix 7.x

I have a procedure stored in informix 7.x, it is called in Nhibernate using the CreateSQLQuery method.

The problem is that all the columns returned by the stored procedure have the same name "expression" and when the procedure is called you can not map the values to an entity.

Is it possible to alias the columns in the stored procedure? o Is it possible to rename the columns in NHibernate?

Stored procedure:

CREATE PROCEDURE ConFactPag
(
    paramCia            CHAR(2),
    paramPla            CHAR(2),    
    paramFechaInicial   DATE,
    paramFechaFinal     DATE    
)

RETURNING 
INT, 
CHAR(4), 
CHAR(10), 
CHAR(100),
CHAR(15), 
CHAR(15),
CHAR(100);

DEFINE v_folio      INT;
DEFINE v_serie      CHAR(4);
DEFINE v_fecha      CHAR(10);
DEFINE v_cliente    CHAR(110);
DEFINE v_importe    CHAR(15);
DEFINE v_saldo      CHAR(15);
DEFINE v_pago       CHAR(110);


FOREACH cFacturas FOR
    SELECT  f.fol_fac as v_folio, 
            f.ser_fac as v_serie, 
            TO_CHAR(f.fec_fac,'%d-%m-%Y'),
            CASE 
            WHEN TRIM(c.razsoc_cte) <> '' THEN
            TRIM(c.razsoc_cte) 
            ELSE 
            CASE    
            WHEN c.ali_cte <> '' THEN
                 TRIM(C.ali_cte) || ', ' 
              ELSE
                 '' 
           END || trim(c.nom_cte) || ' ' || TRIM(c.ape_cte) 
        END AS ncom_cte,
        LPAD(f.impt_fac,6,'0')
INTO    v_folio,
        v_serie,
        v_fecha,
        v_cliente,
        v_importe
FROM    factura f,
        cliente c
WHERE   f.numcte_fac = c.num_cte
        and f.tpa_fac = 'C'
        and f.cia_fac = paramCia
        and f.pla_fac = paramPla
        and f.fec_fac >= paramFechaInicial  
        and f.fec_fac <= paramFechaFinal
        --and f.fol_fac = 534896    

SELECT  SUM(sal_doc)
INTO    v_saldo
FROM    doctos
WHERE   ffac_doc = v_folio and sfac_doc = v_serie and tip_doc = '01';
LET v_pago = '';
IF v_saldo = 0 THEN
    SELECT  ser_pfac || ' ' || fol_pfac || ' ' || fec_pfac || ' ' || 
    imp_pfac
    INTO    v_pago
    FROM    pago_fac
    WHERE   ffac_pfac = v_folio and sfac_pfac = v_serie and numpag_pfac = 1;
END IF;

RETURN  v_folio,
        v_serie,
        v_fecha,
        v_cliente,
        v_importe,  
        LPAD(v_saldo,6,'0'),
        v_pago          
WITH RESUME;
END FOREACH;  
END PROCEDURE;    

C #:

var listFacturas = this.facturaRepository.Session.CreateSQLQuery("EXECUTE PROCEDURE ConFactPag('15','02','2018-06-07','2018-06-07');").List();