You will need to know how an expired contact is recorded. If it marked expired then you would use a does not equal that criteria. If it is a date then it would be everything greater than that date. If it is date that varies and is only recorded when a date or value when the contact expires then you would compare to an empty or null value.
if x is expired then this might take one of these forms.
x <> y (expired indicator
x > 07/11/2008 ( looks for a date after)
x IsNull or x = "" ( looks for a null if that is what is in the data or empty field.
Hope this helps you can find more information in CR Help I believe it is under operators.
Regards,
John W.