Formatting small numbers

[paulmargus]

Among life insurance actuaries, it is customary to quote mortality rates as "deaths per thousand." So, if a mortality rate is 0.00123, I would like to display it as "1.23"

In custom formatting, I have tried the following custom format string:
0.00,%%%
which displays "1.23%%%"
(Here the comma divides by 1000, and each percent sign multiplies by 100, so the result is 100*100*100/100 = "multiply by 1000")

I'm almost ready to tolerate this, but Excel doesn't store it properly for future modification.

Related question: An Investment Yield difference might be 0.00357, which is easily displayed as "0.357%". But how can we display it as "35 b.p."? The closest I've come is the following custom format string:
0.0%%
which displays "35.7%%"

At least Excel stores this one.

 

[venkat1926]

this may look like a trivial answer
why not open another column and multiply by 1000

 

[paulmargus]

Yes, I can simply multiply the number mortality rate by 1,000. But then before using it in subsequent calculations, I must first divide it by 1,000.

Excel does accommodate other similar situations. For example, 0.05 can be formatted as 5% while retaining its underlying value. Similarly, large amounts can be custom formatted, so that $1,234,567,000 can be formatted as $1,234.6 billion by setting the custom format to $#,##0.0,," billion", again with no effect on its underlying value.

In the above example, the comma operator scales down by a factor of 1,000. I'm looking for the comma operator's inverse.