wouldn't this suffice ?

PHP Code: 
=if(countif('[fileB.xls]Sheet1'!$F$2:$F$3000,B3)=0,"",INDEX('[fileB.xls]Sheet1'!$F$2:$G$3000,MAX(IF('[fileB.xls]Sheet1'!$F$2:$F$3000=B3,ROW($F$2:$F$3000)-1,0)),2))