數據累加 第一個缺少小寫字母 (14560)

C2{=CHAR(SMALL(IF(ISERR(FIND(CHAR(ROW($97:$122)),PHONETIC(B$2:B2))),ROW($97:$122)),ROW(A1)))

另解{=CHAR(MIN(IF(ISERR(FIND(CHAR(ROW($97:$122)),PHONETIC(B$2:B2)))*(COUNTIF(C$1:C1,CHAR(ROW($97:$122)))=0),ROW($97:$122))))