Using conditional formatting to highlight a large range based on a smaller range w/specific text

I am trying to filter through 35,000 rows of names to find matching values from another column. In the image below, I wanted to use conditional formatting on Column B in order to find cells that have text that contain/begin with the 9 characters in Column M. This would let me be able to filter Column B to find duplicates I need. I tried to use a formula to accomplish this, but it seems that I would have to duplicate the Conditional Formatting rule for all of the individual values from Column M. I know there has to be a better formula for this.

Any help with this is appreciated.