meelis
If I understand you correctly you have a sme server in server gateway mode that is hosting some domains.
You also have another web server (a windows server in this case but the OS does not really matter) behind your sme server and want to access a domain hosted on the 2nd web server, both from the local network and from external to your network, correct ?
Is so then proxypass is the way to go, if all you want is port 80 access. I'm not sure if access issues with https port 443 were fixed or not.
Firstly remove any existing port forwards or other settings you may have made trying to get this working, and return your sme server gateway to standard settings.
1) Configure external DNS records to point the 2ndservervirtualdomain at your sme servers public IP
2) On your sme server gateway remove the 2ndservervirtualdomain name from the Domains panel
3) Then create the proxypass entry as follows with name resolution set to local:
db domains set 2ndservervirtualdomain.com domain
db domains setprop 2ndservervirtualdomain.com Nameservers localhost
db domains setprop 2ndservervirtualdomain.com ProxyPassTarget
http://192.168.2.2/db domains setprop 2ndservervirtualdomain.com TemplatePath ProxyPassVirtualHosts
signal-event domain-create 2ndservervirtualdomain.com
In this case your second server should be on the same LAN so as to be locally accessible from sme eg sme = 192.168.2.1
Remember to include the trailing / after the IP number in the above command
The 2nd servervirtualdomain should then be accessible from the local network due to the localhost setting, and accessible externally due to external DNS records that point it at your sme gateway, which then proxypasses it to your second server.
I just set one up this way and it works OK.