How to add / create a custom field over the Outlook Object Model

Question

Hi,

i'm developing a plugin which analysis every incoming email on the fly. Gathered information from the this process I need to display in a custom created column (over Outlook i can do that with the field chooser but only available fields).

The question is now how the heck I'm able to add this. I searched the web for the past 2 hours without to find even one single hint about it :-(

Currently I only target Office 2010.

thanks in advance for any hint / solution.

update: in the meanwhile i figured out that what i search for is the Microsoft.Office.Interop.Outlook.OrderField but there is no way so far to extend it.