Find/Format not quite duplicate values between two columns

I have two columns of numbers. Column B is the longer column. Column A is far shorter than Column B. All of the cells in Column A can be found in Column B somewhere. I need to highlight those cells in Column B. The problem is that they aren't quite identical values because the last digit in B cells has been removed from the A cells. Column A = 12 digits, Column B = 13. Thus, I can't do conditional formatting to highlight the Column A cells that are somewhere in Column B. I also can't delete the first 12 digits of B because I won't know which cells in Column A they correspond to.

The ideal end result is to have the Column B cells that match the Column A cells formatted (highlighted).

Thanks!