My company has just started using an application called AS2 to send data
securely to ASDA/Wal-Mart. This application relies on communication from
wal-marts 6 ipaddresses using any port greater than 1023. I have setup
filters to allow any traffic from these 6 ipaddresses to come in. However
the server application which runs on a PC (which has a fixed ip address)
doesn't seem to get the packets.

What I think the problem is, is, the traffic is hitting my public
interface but doesn't know where to go there after. What i think i need
is a route to say when you hit my public interface route through to the
fixed IP on my PC.

I am struggling a bit with this any help would be great.