I have two fields. One is named "Register Date" that contains the date when an incident changes its status. The other one is called "Status" and tells me the status that the incident had from the date on the "Register Date". So, for each of the different status an incident can be, I have in a separate field the date when it changed to this status. I would like to crete a new field called "Date Opened" that would give me the date (from "Register Date") when the incident was set into "Status" opened, but I don't know how to do it.
To make it clearer, I have a table like this:
ID Register Date Status
5 10/03/2012 Opened
5 11/03/2012 Assigned
5 12/03/2012 Closed
How could I create a new filled called "Opened date" that would be 10/03/2012?