access redmine for client outside LAN

Hello,

We have BitNami Redmine 1.3.3.stable running on Debian 6.0 on vmware host (ESXi 5.0).

Apache is configured to listen on port 8080. So adress is redmine.domain.local:8080

In LAN all works fine.

We want acess Redmine from outside. So I set port forwarding from 8800 to 8080. Link from outside is remote.domain.sk:8800

And there is problem, browser show me adress change from remote.domain.sk:8800 to redmine.domain.local:8080/redmine but display only error message "cant find server redmine.domain.local:8080"

Our internal domain server is MS Small business server 2011 (physical).

Port forwarding on another services work corectly, but I cant verify it on another apache server.

Thanks for any help or advice.