I have a simple formula (A1*B1*C1)/((A1*B1*C1)+(D1*E1*F1)+(G1*H1*I1)).
However there are times when the values of D through F or the G through I
denominators can change into letters (if D changes to a letter so do E and
F, same happens to H and I if G changes to a letter). I need the formula to
complete the calculation by assuming any value that becomes a letter as zero.


Thanks for your help.

Regards,

ZUO