Mac Outlook 2011 – looking for rule help

Hi,

I was curious if there's a way to create a rule that contains both ANDs and ORs - such as:

if from contains AAA

OR

if from contains BBB

OR

if from contains CCC

AND

date received is greater than 21 days

Delete email

But this would need to work not on the incoming email, but the mail in my inbox.  I was able to create something but it would just work on the incoming email and that's not going to be 21 days old, so it'd never work.  

Also tried working with a filter, but similar issues with the OR and didn't find an option to delete the email.  

Maybe it's a conspiracy to see how huge my inbox can get?  LOL  But I'd like to find a way to filter out old emails that aren't needed any more.  

Thanks,

Chris