You have this:

Col A has about 25,000 cells (len = 73).
Col B has about 3,000 cells (len = 44).

In column C (25000 cells), put the first 16 characters of column A:
=left(a1,16)
and drag down 25000 cells

In column D (3000) cells, put the first 16 characters of column B.
=left(b1,16)
and drag down 3000 cells

In column E (25000) cells
put this formula
=isnumber(match(c1,d:d,0))

Now filter and show only the trues or falses.

You can delete the mismatches by showing falses
you can keep the matches by copying the visible cells (in column A) and pasting
them to a new sheet.

GARY wrote:

Hi Dave,

I still must be doing something wrong.

Maybe if you will re-give me exact, step-by-step instructions I can
follow them more carefully.

Thanks,

Gary

--

Dave Peterson