They can set a domain level password policy by editing the 'default domain security policy'. Inside the policy navigate to Security Settings > Account Policies > Password Policy. From there you will see the options to change.
The security policy is domain wide but you can override it for specific account by turning on 'password never expires' for the account in AD Users & Computers.
Let me know if you have any questions or if I didn't understand you.
Thanks,
Keith