前後相反 統一規格 (12631)

F2=IFERROR(INDEX(A$1:A1,IFERROR(MATCH(A2,A$1:A1,),MATCH(MID(A2,FIND(":",A2)+1,9)&":"&LEFT(A2,FIND(":",A2)-1),A$1:A1,))),A2)

另解=IFERROR(INDEX(A$1:A1,-LOOKUP(,-MATCH(IF({1,0},MID(A2,FIND(":",A2)+1,9)&":"&LEFT(A2,FIND(":",A2)-1),A2),A$1:A1,))),A2)