Blocking a user on registration based on regex textual comparison

Hello. I have been having trouble for the past few months with a user named Brenda trying to spam my site. She always signs up with the name Brenda something or other.

I am trying to do a textual comparison upon user registration which will automatically block a user if their username contains the word 'brenda'.

In the first textual comparison field, I am using a token for the raw user name input.
In the second textual comparison field, I am not sure what to put.

I saw this: http://drupal.org/node/880924 where it says that I should use something like [test|sample|example ]

But this doesn't seem to work. Any help would be greatly appreciated.