總和 指定起訖月份 (14420)

B12:B14{=SUM(VLOOKUP(A12,A$2:M$4,ROW(INDIRECT(MATCH(C$8,$1:$1,)&":"&MATCH(C$9,$1:$1,))),))

另解=SUMPRODUCT((MATCH(C$8,$1:$1,)<=COLUMN(B:M))*(MATCH(C$9,$1:$1,)>=COLUMN(B:M))*(A$2:A$4=A12)*B$2:M$4)