Email parser rule will only parse emails with an exact match? What madness is this?

Email parser rule will only parse emails with an exact match? What madness is this?

I finally got myhead around deluge and scripting, but wondered why my parser wasn't working. (https://help.zoho.com/portal/en/community/topic/extract-11-digit-number-in-any-position-from-enail-subject)

Problem:
  1. There are *zero* characters or phrases that are guaranteed to exist in my inconing emails.
  2. The only certianly is an 11- digit number as that's auto-generated by the supplier we use.
  3. The "Subject - is" or "Subject - Contains" in the "Email Criteria" of the parser rule will not accept a wildcard - they apear to insist on matching a word/character or deny access to the parser!
So, I have a script that can look at the entire subject, extract a number, and match it to assign to a claim or an unassigned list, but I can't make the Email Parser simply look at *every* email that is from a specific addres so the script can be triggered! 

What gives - why not allow the user to look at any email in the parser and let the script do it's job!

Surely they wouldn't deny the option of a user wishing to parse *all* emails regardless?

Any help appreciated - am I missing something?