Networkdays in sumproduct

Hi,
is there some way to get this function workin:

Formula:

=IF(G2>0; IF(O2>0;((

SUMPRODUCT(($G$2:$G$7000>0)*($O$2:$O$7000>0)*($G$2:$G$7000<=G2)*(O2<=$O$2:$O$7000)*(U2))

+SUMPRODUCT(($G$2:$G$7000>0)*($O$2:$O$7000>0)*($G$2:$G$7000<=G2) *(G2<$O$2:$O$7000)*($O$2:$O$7000<O2)*Networkdays(($O$2:$O$7000);G2))

+SUMPRODUCT(($G$2:$G$7000>0)*($O$2:$O$7000>0)* (G2<$G$2:$G$7000) *($G$2:$G$7000<O2) *(O2<=$O$2:$O$7000) *Networkdays(O2;($G$2:$G$7000)))

+SUMPRODUCT(($G$2:$G$7000>0)*($O$2:$O$7000>0)*(G2<$G$2:$G$7000)*($O$2:$O$7000<O2)*Networkdays(($O$2:$O$7000);($G$2:$G$7000)))

)/U2)-1; ""); "")

The important part is that "networkdays" somehow responds with an array.
The formular should calculate the capacity utilisation in the time specified from "G2" to "O2" and will be applied on all 7000 lines ("Gx" to "Ox").
I translatet this excel code from spanish. I hope that everything is correct.
Thanks a lot for you patience if you look over my problem.