CCK Date Filter or Argument Question

I am setting up a view with Views Calc where I want to display the last 7 days of data for a specific cck date in a node.

So if I pull up the node with cck data 7/27/12 I pull the nodes that have cck date data from 7/21/12 to 7/27/12. And if I go to the node with cck data 6/27/12, I pull the nodes that have cck date data from 6/21/12 to 6/27/12.

I am not sure how exactly to set this up. I can filter by the current date, but I can't figure out how to filter based off a date that is in the past. I'm not even sure Filters is the right way to go, should I use and argument?

If anyone can point me in the right direction, that would be great.

Thanks!