In this case, I would say, you would need a script that would run automatically on startup.
To execute scripts or commands on startup you can put them in /etc/rc.local file.
To not bother editing current config files through commands and how to not mess up what's inside - I would suggest just swapping the current configuration with the new one, that you would store somewhere in the memory of your device.
rm <currentfileLocation> removes the file from the location
cp <newconfig> <destination> copies your new config to the destination where the old config was located.
/etc/init.d/network restart to restart network service and load the new config.
And above is all if you want to place something into your /etc/config/network. But if you want to just execute these commands like in CLI, then just put them into rc.local file and it should be fine.