Installing Employee Self Service on a standalone Windows server

We are attempting to install ESS on a stand alone Windows server. The Portal and other Lawson applications reside on another server inside our fire wall. ESS will reside alone on its own server. I am seeing that Lawson install does not suggest this configuration - it has installing on the same server with the rest of the other components or installing with the Portal software on a server outside a firewall. I am wondering if anyone has tried this implemention we are looking at where the ESS app is not on the same server as the other apps (including the Portal apps) and if so, can you please share any things we are not immediately knowing - like how to map LAWDIR and WEBDIR correctly, etc) . Thank you in advance for your thoughts and ideas. -carol