我有一個笨法子：

公式：

=IF(OR(ISERR(FIND("1",A1)),ISERR(FIND("1",B1))),"",1)&IF(OR(ISERR(FIND("2",A1)),ISERR(FIND("2",B1))),"",2)&IF(OR(ISERR(FIND("3",A1)),ISERR(FIND("3",B1))),"",3)&IF(OR(ISERR(FIND("4",A1)),ISERR(FIND("4",B1))),"",4)&IF(OR(ISERR(FIND("5",A1)),ISERR(FIND("5",B1))),"",5)&IF(OR(ISERR(FIND("6",A1)),ISERR(FIND("6",B1))),"",6)&IF(OR(ISERR(FIND("7",A1)),ISERR(FIND("7",B1))),"",7)&IF(OR(ISERR(FIND("8",A1)),ISERR(FIND("8",B1))),"",8)&IF(OR(ISERR(FIND("9",A1)),ISERR(FIND("9",B1))),"",9)&IF(OR(ISERR(FIND("0",A1)),ISERR(FIND("0",B1))),"",0)