Parameter for query

Hello. I am trying to add a parameter to a report that was written for me by someone that I haven't been able to contact (and unfortunately I am unfamiliar with XML but understand some SQL). The code for the report is

<report title="Active Demographics" description="Reports Active Patient Addresses" active="1">
<query>
select last_name, first_name, address, city, province, postal
from demographic where provider_no = {provider_no} and patient_status = 'AC' order by last_name, address
</query>
<param id="provider_no" type="list" description="Provider Number">
<param-query>select provider_no, CONCAT(last_name, ', ', first_name, ' (', provider_no, ')') from provider order by last_name;</param-query>
</param>
</report>

The report interface has one box that allows you to select the provider number from a list of providers in the database and run the report.
I would like to add another box that allows me to specify the patient status as either ('AC' OR 'IN') or 'AC'.
Can anyone suggest how I can write this parameter?

Thanks for your time.

Alexandra