[Orgmode] Meta-grouping properties?

[Sven Bretfeld]

Hi all

Is it possible to define meta-groups for certain properties? For
example:

* TODO Some Task
  :PROPERTIES:
  :dowith:   PR-Group
  :END:
* TODO Another Task
  :PROPERTIES:
  :dowith:   John
  :END:
* TODO A Third Task
  :PROPERTIES:
  :dowith:   Mary
  :END:

The PR-Group consists of four people including John and Mary. So when
John is with me, I would like to be able to build an agenda view that
shows "Some Task" and "Another Task", when Mary is with me, "Some Task"
and "A Third Task" should show up. 

This would be easiest if I could make org aware who actually belongs to
the PR-Group and then just filter the Agenda View for John (or Mary
resp.). 

Is that possible?

Greetings,

Sven