@akbooer As @RHCPNG said, you can easily do this, once you have a running setup by copying the contents of /etc/cmh-ludl/ to a local folder, restart the container with that folder mounted to /etc/cmh-ludl/.

The difference between using a volume and a folder mount is (amongst other details) how Docker handles this at first startup. When using a volume, Docker copies the contents of e.g. /etc/cmh-ludl/ when it is started with a empty new volume, to that volume. As of that moment all changes are kept in the volume and survive container restarts and updates.
A mounted folder also preserves all settings, but in contrary to volumes, Docker does not copy the original contents of the mount target to the folder at first startup. This means you need to store create the files needed in /etc/cmh-ludl/ yourself, which makes it harder to initially get start (except for one who masters openLuup 😉 ).