You'll want to create the new world (by hand, previous to using it), and then you can just open it, using this command:
http://www.gammon.com.au/scripts/function.php?name=Open
Even if you made the world a skeleton (with no login, or password, or anything else) this is a much easier way of doing it. This way you could even pre-set some aliases/triggers that you may need in that world.
I suppose if you wanted to create an arbitrary number of worlds, you could use the same world file as a base, and instead of merely opening them, you could copy them to a new file and then open that new file, so your base world would remain the same.
You could even use your current world file for this base file.