How do I set up passthrough for a certain port number? Our automation system runs on port 2025 (a constant connection) and I want it to have direct 'pass through' the firewall so it will never be dropped.

Outbound traffic from the LAN going out to the Internet is always allowed to passthrough without any setting changes.

If you want Internet access to your system from outside, you must setup virtual server port range mapping and map port 2025 from your public IP address to your internal system IP addresss.