Set CC notification date and cron job

So happy with s2member thus far.

We offer an ongoing subscription model and are going onto another step to try and head off credit card expirations and hopefully lessen our EOT issues.

Here is what we have done.
We’ve added an additional field to the registraiton profile fields using the options in the interface to store notification dates to notify customers of expiring credits cards. This date is one month prior to the expiration date. This step has been successfully done and is populated through jQuery based off of user’s entry in the expiration fields. The additional field is the required date format dd/mm/yyyy as selectable in s2. For clarification, we’ve given this the id cc_exp_notification_date

What we would like to do is have a bit of help on the next bit. Our PHP isn’t the greatest.

1. properly run a query that checks for any users with cc_exp_notification_date values on/before today for users with level 1 access and above so we can send an “update cc reminder” email. Our heads were spinning trying to query s2member custom fields.

2. tie this query into the daily wordpress/s2 cron job

Any help you could provide would be greatly appreciated!

FYI, we are using the authnet pro forms.