This is an easy one:

"IRR guess = "0%

I tried this as a custom format, but it doesn't work if the value is
negative. In fact, if the value is minus 3%, it ends up showing as (with
the negative sign showing up in front of the label):

-IRR guess = 3%

What do I do to the custom formatting to allow it to show negative values as
negative?

Thanks!
Dean