Mapping Associations using composite-key element ,property-ref attribute and <formula> element

I want, join should be performed on 3 properties out of which 2 are normal properties and one is part of composite key.
How can i specify these 3 properties inside <properties> tag ?

The problem is with useType mapping.

org.hibernate.PropertyNotFoundException: Could not find a getter for compProductBasicBO.useType in class com.tietoenator.lis.db.impl.product.bo.ProductBasicBO
at org.hibernate.property.BasicPropertyAccessor.createGetter(BasicPropertyAccessor.java:282)
at org.hibernate.property.BasicPropertyAccessor.getGetter(BasicPropertyAccessor.java:275)

<class name="Product" table="PRODUCT"  optimistic-lock="version">
      <id name="productId"  column="PRODUCTID">
       <generator class="assigned" />
       </id>
      <one-to-one name="productBasic" class="ProductBasic" cascade="save-update" property-ref="activeProduct">
        <formula>'001'</formula>
        <formula>TIMESTAMP ('9999-12-31 00:00:00.0')</formula>
        <formula>PRODUCTID</formula>
      </one-to-one>
    </class>  
      
      <class name="ProductBasic" table="PRODUCTBASIC" optimistic-lock="version">
      	
	 <composite-id name="compProductBasicBO" class="com.tietoenator.lis.db.impl.product.bo.CompProductBasicBO">
	   <key-property name="productId" column="PRODUCTID" ></key-property>
	   <key-property name="useType" column="USETYPE" ></key-property>
	   <key-property name="startTimeStamp" column="STARTTIMESTAMP" ></key-property>
	</composite-id>
	
	
	 <properties name="activeProduct">
	     
	     <property name="endTimeStamp" column="ENDTIMESTAMP" ></property>
	     <many-to-one name="productBO" class="ProductBO" column="PRODUCTID" insert="false" update="false"/> 
	</properties>
      </class>

If i don't use seperate class for composite-id, then it is working fine :