FORMULA I NEED HELP WITH:

=SUM((--(YEAR(Z4:Z3500)=2007))*(AN4:AN3500="Referred to Tx))*(AN4:AN3500="AC
Initiated"))

MY PROBLEM

In Row Z I am listing dates, and in Row AN I am listing whether or not
clients were Referred to Treatment (Tx), and whether or not they began
treatment (e.g. AC Initiated). I can get the above formula to work with only
one search criteria in Row AN and the appliable date range in Row Z (e.g. the
year 2007), however I cannot get the formula to work, when I enter 2 search
criteria in Row AN (Referred to Tx and AC Initiated). Can an array formula
search the same row twice (AN), and count all clients who were seen in 2007
who we (a) Referrred for Tx and/or (b) Initiated Tx (eg. AC Initiated).

Any help would be much apreciated!

Dan