Regex Email Filters

Hello all -

First time poster here.  The new email system has taken away the "does not contain" option for making an email filter, and with it then my favorite filter. I had a final filter set that said: If To does not contain mylastname AND cc does not contain mylastname then put the email in my spam folder.  (Mylastname would have to be in bcc).  Thus many list servers would go to spam.  If I found I wanted one of those upon review, I would make allowance for that in an earlier filter.  Worked like a champ for 20 years.

So I set out to make a replacement with regex, and it's been difficult. I am not a regex noob, but there are many flavors of it.  Cox seems to be using the Open-Exchange version (I know because that's what complains about my errors ) but I can't find out anything about what and which that engine supports. If anyone knows of a pertinent link, I would appreciate the steer.

I do believe that Open-Exchange does not support look-ahead, which makes exclusionary matching very hard. For those of you who have successful regex rules, would you please reply with an example? I presume that if the appropriate string is found, the rule is satisfied and executed.  Is all that goes into the rule the regular expression?

I ask because I've tried the very simple and too broad rule of [^lettersofmylastname] to force a result, and that doesn't work. I'm figuring my approach is incomplete.  Is there a Cox tutorial out there?  I'd appreciate any lessons learned.

Thanks for reading, and season's cheer.