Follow these steps to add additional columns in your View Pane.
Go to View > View Settings
Figure 1: Outlook View Ribbon, View settings command
Figure 2: Columns button within View settings
You are now able to select the addition Fields to be displayed in the default view. You are also able to remove unwanted fields from your view from within this screen
Choose the field (s) you wish to add and click the Add button
Figure 3: Adding columns within view settings
In this example the CC field has been added to the default view.
You will now see the CC column in your Navigation Pane:
Figure 4: Newly customized view