I am trying to figure out a quick way to compare two columns of text for
common phrases. The two columns - one of which has over 30k rows - have cells
with company names. I simply need to identify the companies that are listed
in both columns. However, because the same company may be written with slight
textual differences in either column (i.e. "3M" versus "3-M"), I need to
search based on the proximity of characters to each other (i.e. "3" and "M,"
in that order, within a couple of characters of each other). Ideally, I would
also like tally of the number of instances of overlap (one column has no
duplication of company names while the other has extensive duplication -
although, again, even within a single column the same company may be listed
under several different variations in spelling).

I would greatly appreciate any guidance! Thank you.