隨機取不重複字元 (14383)

F2:L13{=IF(COLUMN(A1)>$D2,"",MID($B$2,SMALL(IF(COUNTIF($E2:E2,MID($B$2,ROW($1:$9),1))=0,ROW($1:$9)),RANDBETWEEN(1,LEN($B$2)+1-COLUMN(A1))),1))