Apache IP Address and NIC Messup

I have Apache webserver in front end acting as reverse proxy for application servers. Now the Problem is. I have 4 network cards and 5 IPs on the apache httpd webserver machine. I have configured apache to listen on first IP address 10.10.1.1 port 80 via Virtual host.

Now when a client hits my apache webserver it goes to the application server to fetch data the problem is.. apache is using 4th IP address that is 192.168.100.5. I dont want apache to use 192.168.100.5 IP Address to connect to the application server. I want apache to use 2nd IP Address 10.10.2.1 to connect to Applicaton server at the backend.. is it possible? How can i accomplish this ?

Details:
Webserver IPs
NIC1 - 10.10.1.1
NIC1 - 10.10.2.1 - (additional IP)
NIC2 - 172.16.0.1
NIC3 - 202.156.34.34
NIC4 - 192.168.100.5

App server IP
10.10.2.12

please let me know if there is a solution to change the IP Addresses of outgoing apache connection

This could be a network routing issue on the web server - when your Apache session tries to connect to the remote machine it follows the normal routing table. I'm assuming you have a subnet for each of the NICs, so you want to do a 'route add' for the subnet (probably 10.10.2.*) that goes off to through the right device (eth1 or whatever it's called). Something like this:

route add -net 10.10.2.0 netmask 255.255.255.0 dev eth1