Filter Addresslist by OU?

All -

I am currently running this powershell to create an addresslist that searches for any contacts that ends with "blah.com". The problem is I want to narrow this down so it does not search the entire domain, but rather focus on 1 OU. Is this possible with the "new-addresslist" command? I am not sure how to do this. I have attempted to use "recipientcontainer" but from what I'm reading, you can't use that when you are using "recipientfilter".

The current command I have is: (which does not narrow to the specific OU)

new-addresslist -name "Blah Contacts" -recipientfilter {(recipienttype -eq 'MailContact') -and (ExternalEmailAddress -like "*blah.com")}

Select allOpen in new window

Thanks!