Reverse Proxy

I have configured reverse proxy through apache...conf file is attached

My reverse proxy has a public ip.it is redirecting the request to 172.16.1.43 which is http

server.....Now i have a link in Http server's home page which will redirect the request to

another Lan zone machine (172.16.1.56).........

It is working fine in Lan zone.........but while I am accessing from internet the request

is redirecting through reverse proxy to my Http server which is currently in Lan zone

But further link can't be resolved.I have Cisco pix firewall in between...which have

necessary access list entries & nat charts..........What should I do????

DNAT ???