PMing members from MySQL?

[HouseAddict]

So I use vbulletin's email manager to send newsletters to our members. I recently installed tracking in these emails to log usernames that viewed the email.

I'm interested in setting up a system to PM members that haven't been logged as viewing the newsletters to warn them the emails might not be getting through spam filtering.

I've got this query

SELECT username
FROM `user`
WHERE username NOT
IN (

SELECT username
FROM `tracking`
WHERE logcode = 'newsletter'
)
AND options &16 !=0

This will give me a list of all the usernames that have not been tracked as viewing the newsletter. My question is how do I go about using this information to send them a PM?