[Zope] Can I relocate data.fs?

[kent@springfed.com]

>At startup Zope looks for a file called custom_zodb.py which can=
 contain a
>definition of an alternative storage. It is usually used to=
 specify ZEO,
>bsddbStorage.Full, etc, but it can also be used to specify a=
 FileStorage in a
>different directory.

I have been unable to find the syntax for this definition.
if I copy the contents of var to c:\new\location\var
what should I put in custom_zodb.py  ?

Thanks,
Kent