if i understand this correctly , you want to have First and Last 4 Characters or Unique value,
see if it works

=Left(IFERROR(INDEX($A$2:$A$118,MATCH(0,COUNTIF($A E$1:AE25, $AE$2:$AE$118),0)),""),4) & right(IFERROR(INDEX($A$2:$A$118,MATCH(0,COUNTIF($A E$1:AE25, $AE$2:$AE$118),0)),""),4)