How can I add a new field to all outlook contacts?

[PTrader34]

I'm using Outlook 2007, and I'm trying to add a new field to an existing database of contacts. I use a template to input data for new contacts, but sometimes I may want to add a new field. How would I be able to make this new field available to all existing contacts?

For example (see picture below), if I wanted to add in the field "Display As" onto the template, but also wanted the field to be available to all existing contacts, how would I be able to do this?

http://i.imgur.com/nyokd.jpg