In order to inject conversation scoped objects into JSF backing beans, I currently do the following :

Define a request based backing bean in faces-config, use setter injection to inject #{someObject} (defined as a conversation scoped variable in my flow definition)

Code:
<managed-bean>
<managed-bean-name>backingbean</managed-bean-name>
<managed-bean-class>com.acme.backingbean</managed-bean-class>
<managed-bean-scope>request</managed-bean-scope>
<managed-property>
<property-name>someObject</property-name>
<value>#{someObject}</value>
</managed-property>
</managed-bean>
My flow definition defines the someObject variable in conversation scope

Code:
<flow>
<var name="someObject" scope="conversation"/>
...
</flow>
My spring beans configuration contains the definition of the someObject bean

Code:
<beans>
<bean id="someObject" class="com.acme.SomeObject" scope="prototype"/>
...
</beans>
For every request, the backing bean get's re-created, and injected with the same conversation scoped object during the flow (behavior that I want).

Suppose I don't want to use faces-config to define my backing beans, but I want to use spring beans as backing beans, how do I inject the flowscoped someObject into the spring bean ?

I removed the entry in faces-config.xml, and defined the backing bean in my spring beans configuration :

Code:
<bean id="backingbean" class="com.acme.backingbean" scope="request">
<property name="someObject" ref="???"/>
</bean>
Spring allows me to refer to #{backingbean} via EL without a problem, but how do I inject someObject ? What do I need to put as a ref or value attribute ? If a use ref="someObject", I get a new someObject injected on every request. How do I tell Spring to lookup the conversation scoped object belonging to my flow (as is the case when the backing bean is configured in faces-config) ?