各區销售额 (11116)

F3=SUMPRODUCT((LOOKUP(ROW($3:$15),ROW($3:$15)/(A$3:A$15<>""),A$3:A$15)=E3)*C$3:C$15)/2

另解{=INDEX(C:C,MATCH(1=1,MATCH(E3,A:A,)-1<(B$3:B$15="小计")*ROW($3:$15),)+2)

另解=VLOOKUP("小计",OFFSET(B$2:C$2,MATCH(E3,A:A,)-2,,20),2,0)