Looking for a sample function to find a location for org-capture

[Charles Cave <charles_cave@optusnet.com.au>]

I'm exploring the many features of org-capture and I see the
documentation about a function for finding the location for refiling.

I would like to see some sample code on how to do this.

At the moment I am using a date tree to file my TODO items and
notes. (I am writing an article about this and will publish soon)

Let's say I had a headline structure for weeks of the year and I would
like a function to add an item to the heading corresponding to the week
of the year. Today (12th Aug) we are in Week 32. 

What would the function be to file under the appropriate heading:

* 2010
** 2010-Week-28
** 2010-Week-29
** 2010-Week-30
** 2010-Week-31
** 2010-Week-32
** 2010-Week-33

Could the function create the heading if it didnt exist . just like 
org-capture handles creation of new brances on a date tree?


Charles