Query sql = session.createQuery("from CScontrinoVO as ay where ay.pk.cbara=? and ay.pk.filia=? and ay.spedizioni.magcbt=?");

      sql.setString(0, "aa");
      sql.setString(1, "bb");
      sql.setString(2, "cc");

CSContrino.hbm
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping>


   <class name="vo.as400.CScontrinoVO" table="sdgtwb_dat.aynau00f" lazy="false" >

         <composite-id name="pk" class="vo.pk.CScontrinoPK">
              <key-property name="cbara" column="cbar$a" type="string"/>
              <key-property name="filia" column="fili$a" type="string"/>
        </composite-id>





        <property name="staga"  column="stag$a" type="dao.hibernate.TrimmedString"/>

        <property name="modea"  column="mode$a" type="dao.hibernate.TrimmedString"/>
        <property name="matea"  column="mate$a" type="dao.hibernate.TrimmedString"/>
        <property name="coloa"  column="colo$a" type="dao.hibernate.TrimmedString"/>
        <property name="varia"  column="vari$a" type="dao.hibernate.TrimmedString"/>
        <property name="cdtga"  column="cdtg$a" type="dao.hibernate.TrimmedString"/>
        <property name="tgsia"  column="tgsi$a" type="dao.hibernate.TrimmedString"/>
        <property name="pvena"  column="pven$a" />
        <property name="pacqa"  column="pacq$a" />
        <property name="de20a"  column="de20$a" type="dao.hibernate.TrimmedString"/>
        <property name="dcola"  column="dcol$a" type="dao.hibernate.TrimmedString"/>
        <property name="dcmpa"  column="dcmp$a" type="dao.hibernate.TrimmedString"/>
        <property name="ggspa"  column="ggsp$a" />
        <property name="mmspa"  column="mmsp$a" />
        <property name="aaspa"  column="aasp$a" />

        <many-to-one name="spedizioni" class="vo.as400.CSpedizioniVO" lazy="false" update="false" insert="false"   not-null="true">
      <column name="GGSP$A"/>
      <column name="MMSP$A"/>
      <column name="AASP$A"/>
      <formula>20</formula>
      <formula>'V'</formula>
      <formula>(TRIM(SUBSTR(NDOC$A,1,8)))</formula>
      
      
   </many-to-one>

        </class>


</hibernate-mapping>

Spedizioni.hbm

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping>


   <class name="vo.as400.CSpedizioniVO" table="sdgtwb_dat.bspte00f" lazy="false" >

         <composite-id name="pk" class="vo.pk.CSpedizioniPK">
              <key-property name="ggosbt" column="ggosbt" />
                        <key-property name="mmosbt" column="mmosbt" />
              <key-property name="aaosbt" column="aaosbt" />
              <key-property name="soosbt" column="soosbt" />
              <key-property name="sbspbt" column="sbspbt" />
                   <key-property name="nbspbt" column="nbspbt" />
       
        </composite-id>





        <property name="magpbt"  column="magpbt" />
        <property name="magcbt"  column="magcbt" />
       
   

        </class>


</hibernate-mapping>