A formula:
=IF(COUNTIF($A$1:$G$21000,A1)>=$I$1,A1,"-")
in cells K1:Q21000, working on random 4 digit numbers in A1:G21000 (not random generated at each calculation, just plain, static values) takes about a minute and a half here.


Do you have an old machine?
What are you aiming to do (in words)?