Select the folder for which you want to create the formula field.
On the View menu, select Current View, and click Customize Current View.
On the View Summary dialog box, click Fields.
Click New Field.
In the Name box, type a name for the field.
In the Type box, click Formula.
Click Edit.
To insert a function in the formula, click Function, point to the function set that you want, and then click the formula that you want.
For information about the functions and operators that you can use,
see Microsoft Visual Basic Help available from the Visual Basic Editor (on
the Tools menu, point to Macro, and then click Visual
Basic Editor).
To insert a field in the formula, select the argument that you want to replace, click Field, point to the field set that you want, and then click the field that you want.
For information about standard fields for each item
type in Outlook, click .
Click OK twice.
Click Move Up and Move Down to position the field between the other fields in the
view.
To remove the field from the view, click Remove.
Notes
Formula fields are updated with any change to a view. For example, if you change the width of a column, the formula fields are updated.
You cannot sort, group, or filter the contents of a formula field.