Wip Turnover crosstab format?

[#1]

I am not really sure how to go about doing this. I am basically familiar with expression writing, but not much.

We want to create a WIP(Work in process) turnover list, which shows the change in WIP per week. So it would show for each week, the total value open, and the total Count open. Fields I have available are Completed Date (blank if currently still open) Created date, and the cost field.

What I am not sure how to do is show for the past 30 days (weekly about 5 weeks) what the total count and value was. How do I carry the data over to the next week if it is still open?

Example:

                               06/12/2011      06/19/2011    06/26/2011      07/03/2011      07/10/2011

Value:                       16,282.23       98,343.69     140,140.61          855.28          1,089.21

Count:                          33                  87               275                   138                 13