Tomcat – How to use Apache to redirect to IIS on a different port

I have Apache configured with jk_mod to redirect to several instances of tomcat. Apache is listening on port 80, and depending on the URL it receives it will redirect to a different tomcat instance (each tomcat instance listens on a different port). I am adding a new IIS server listening on a different port, but jk_mod fails because it is looking for tomcat. I see the following error in jk_mod.log:

[Fri Dec 10 14:43:30 2010] [7392:6864] [error] jk_ajp_common.c (2204): (worker-bugs) Connecting to tomcat failed. Tomcat is probably not started or is listening on the wrong port
[Fri Dec 10 14:43:30 2010] [7392:6864] [info] mod_jk.c (2364): Service error=0 for worker=worker-bugs

What should I use to send clients to IIS from Apache?