How to configure load-balanced servers

Problem:
We have 2 Windows 2003 based server boxes in a load-balanced cluster. Each
one has to run Apache2 + mod_jk2 + Tomcat5.5 . And each server machine is
equipped with 2 NICs (2 IP addresses), with one of them being also mapped
to a third IP-address which is common for the whole load-balanced cluster.

Question:
With what IP-address do I have to configure each Apache2 and Tomcat5.5? All
requests from the outside are to go through the commong load-balancer
IP-address, and from there to one of the Apache2 servers, which then
finally is to serve static pages directory and to pass on servlet requests
to the Tomcat5.5.

Any help or hints appreciated.

J.Neuhoff