Creating Mac Mail rule using exact phrase

In Mail for Mac (mail.app), I wish to create filtering rules that only trigger for an exact phrase. Amazingly, Apple does not seem to have provided us an easy way (or indeed any way) to do this. I have seen mentions elsewhere of using boolean phrases, but I am wondering if people are confusing the ability to use those in searches of Mail.

Example: if an email content contains the exact phrase "The Rich Investor", I wish those emails to be moved to a particular mailbox. I first tried the most obvious way, put the phrase in quotation marks, however this isn't recognised. (yes, why not, I also wondered?)

I then tried boolean, i.e. if message content contains: 'The AND Rich AND Investor' then move message. This didn't work.

Any other suggestions please?