Host WAN IP

Hello bigneo7, 

Thank you for reaching out to the community, if your requirement is to translate outgoing traffic from the internal network to external resources on the internet.
Then you may refer the following here: https://docs.sophos.com/nsg/sophos-firewall/18.5/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/NATRules/RulesPoliciesCreateSNATRule/index.html

Hi bigneo7

Thank you for reaching out to the community, you can refer to the following link to meet your requirement with DNAT

https://docs.sophos.com/nsg/sophos-firewall/18.5/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/NATRules/RulesPoliciesCreateDNATAndFirewallRulesForInternalServers/index.html 

If you have subscribe the license for WAF on Sophos XG please use WAF as per the below link : 

https://support.sophos.com/support/s/article/KB-000036712?language=en_US 

Thanks and Regards