I think you could use:
Try different configurations on a test machine, eg. vmware box before putting live.
However, you need to ask yourself exactly why you want that kind of configuration, ie adding 2 extra folder names to the config?
If it is because you are migrating from another control panel into ispconfig, I would suggest you don't try to make ispconfig fit your current layout, rather treat each site individually and migrate into new ispconfig structure.