Compare columns A & B, list unique rows of column B in column C

This sounds like it should be relatively easy to do, but so far I am not having any luck. I would like to compare column a and b, then list the unique rows in column b in a third column. I have looked at Advanced Filtering, but keep getting the dreaded "Extract range has a missing or illegal field name" message. Thanks in advance for any and all advice.

newdoverman, I appreciate the quick response. I was able to plugin my data, comparing 2000 rows to an index of 7000 rows, to your spreadsheet and was able to modify the formula in column C to identify the unique rows in column B. Forgive my beginner knowledge of Excel, but I am having difficulty modifying the formula in column F to list any more than 25 unique rows from column B.

Here is the modified formula from C2, which seems to be working:
=IF(COUNTIF($A$2:$A$7810,B2)>0,"",MAX($C$1:C1)+1)

This is the modified formula from F2, which is only returning 25 unique rows from B:
=IFERROR(INDEX($B$2:$B$2362,MATCH(E2,$C$2:$C$2362,0)),"")

I also just noticed that column E is only enumerated to row 26 even though column C identifies 324 unique rows.

I am sure that I am missing something simple, but as I said my untrained eye is blind tonight. Thanks, in advance for your help.

Originally Posted by newdoverman

Sorry for the delay in getting back to you. My internet routing to the forum was lost yesterday and it took a while to get it back. Something between me and Excelforum broke down.

Here is a modification of the file that will go down 20000 rows.

Again, I apologize for not responding earlier but I had no connection available.

No worries, I appreciate your help. Glad your connected again. Thanks, again.