Formula to Count Years Above Zero

[phelbin]

I'm calculating the future value of annuities with several variables, so the FV function isn't an option.

This formula gives me the expected value at the end of the term:

=H6*((1+$G$1)^C6)-$I6*(((1+$G$1)^C6)-1)/$G$1)

In this formula, C6 is the number of years. The math works when the number stays positive, but when it goes negative I need to change the formula.

So for those that go below zero, I need to know at what point it crosses zero. In other words, I need to count the years above zero using the above formula.


Is this even possible?