I have an IRR that seemingly cannot be solved by Excel.

I have a cash flow of $20,000 for two years. The value at the end of the 2nd
year is $43. On my HP 12C it calculates the IRR as -99.79. So I know there is
a answer.

I cannot get Excel to give my any answer other than an error such as #Value.

=IF(ISERROR(IRR((R3C20:RC20,RC38),-0.9)),IRR((R3C20:RC20,RC38),R[-1]C),IRR((R3C20:RC20,RC38),-0.9))

Basically the first portion says if you can't get an answer with the IRR
Guess of -0.9, then try using the IRR from the previous year, else use the
-0.9.

The context is this is a life insurance illustration. I am calculating the
IRR on the Cash Value each year.

In the first year I have a cash flow of $20,000 with a return of zero. I do
not use the IRR function but take the first year CV / Premium and subract.
Result is -100%.

Next year another $20,000 is paid as premium and the CV is $43.

-20,000
-20,000 +43
Excel returns #Value using my formula.

If I strip down my formula by removing the IF condition and only use the
-0.9 guess, Excel returns "#Num".

The only way I can get Excel to calculate the IRR is to manually type in the
-0.9979. BUT Excel returns -99.68%

How can I persuade Excel to return -99.79% instead of an error message?