Let's assume that C3, C14, C25, C34, and C41 contain the following
values...
100
0
150
125
-250
....and we have the following formula...
=SUMPRODUCT(--(CHOOSE({1,2,3,4,5},C3,C14,C25,C34,C41)>0),CHOOSE({1,2,3,4,
5},C3,C14,C25,C34,C41))
....here's how it breaks down...
CHOOSE({1,2,3,4,5},C3,C14,C25,C34,C41)>0 evaluates to:
TRUE
FALSE
TRUE
TRUE
FALSE
--(CHOOSE({1,2,3,4,5},C3,C14,C25,C34,C41)>0) evaluates to:
1
0
1
1
0
Notice that the double negative coerces TRUE and FALSE to their
numerical equivalent of 1 and 0, respectively.
CHOOSE({1,2,3,4,5},C3,C14,C25,C34,C41) evaluates to:
100
0
150
125
-250
SUMPRODUCT multiplies these two arrays...
=SUMPRODUCT({1,0,1,1,0},{100,0,150,125,-250})
....which gives us...
=SUMPRODUCT({100,0,150,125,0})
....and which it sums and returns 375.
Hope this helps!