i found the option to delete duplicates, but i want to delete everything but
duplicates?

i have
column 1 with 2500 names,
column 2 with all the 2500 usernames corresponding to column ones names , and
column 3 with the list of names we need about 600

and i want to filter out of column 1 and 2 all the names that do not match
the column 3 list,
please advice
thanks
ian

If you have in A1:An Names, B1:Bn UserNames, and in C1:Cn the names
you want to match the Names with the user name in D1:Dn, say, you may
applay the following formula in D1:D2500, NOT TO D600,

=IF(ISNUMBER(MATCH(C2,$A$2:$A$2500,0)),INDEX($A$2: $A$2500,MATCH(C2,$A
$2:$A$2500,0)),"")

This formula applied to D1:D2500, will give you the user names of the
names already in C1:C600
But if something is not found it will leave the cell blank, therefore
after applying this formula, you will need to get rid of the blanks.
(this is another thing)
Try it for now, if it does your job and later we will see about the
blank cells.
I am sure a VBA code, or a more expert person would do it better.
If this helps, Leave me a feedback please.
Regards, Totti.