If you backend app server is oc4j then you can go with mod_oc4j module that ships with OHS 10g.
If your backend server is weblogic then use Oracle http server 11g version where in you have mod_wl_ohs file to integrate OHS with weblogic and do load balancing of requests.
thank you for your answer. The backend server needs to be Tomcat in this specific case. Do you know if that would work, too?
In such case you can try with mod_proxy and mod_proxy_http modules.