"Max" wrote in message
...
One way ..

Assume the 2 lists are in cols A and B, in row1 down with
col A housing the 4500 names, col B containing the 400 names

Put in C1:
= IF(B1="","",IF(ISNUMBER(MATCH(B1,A:A,0)),ROW(),"") )

Put in D1:
=IF(ISERROR(SMALL(C:C,ROWS($A$1:A1))),"",INDEX(B:B ,MATCH(SMALL(C:C,ROWS($A$1
:A1)),C:C,0)))

Select C1:D1, copy down to D400

Col D will return all the names in the 400 list in col B which is found
within the 4500 list in col A, neatly bunched at the top, with blank rows
below

Or, with one single formula,
having 4500 names in Ra1, 400 names in Ra2:

{=IF(ISERROR(INDEX(Ra1,SMALL(IF(ISNA(MATCH(Ra2,Ra1 ,0)),
"",MATCH(Ra2,Ra1,0)),ROW(A1)))),"",INDEX(Ra1,
SMALL(IF(ISNA(MATCH(Ra2,Ra1,0)),
"",MATCH(Ra2,Ra1,0)),ROW(A1))))}
FormulaArray aside the first row of Ra2, then to be copied
alongside Ra2.

Bruno