IISPROXY & backend systems

I’ve installed the iisproxy.dll and am able to access my EP 6.0 SP11.3 system.

The issue I have is I don’t know what I need to do to support access to my BW & CRM systems via the proxy. My goal is to have all external traffic for the portal and backend systems pass through the proxy while permitting internal traffic to access the systems directly.

Can someone point me in the right direction?

Thanks,

Greg