Ranking of a selected value

[#1]

Hi,

I've some difficulties to use the RANK function in a chart.

Suppose we have a file with : Country, City and one numeric field ( inhabitants)

I'd like to create a text box with the rank of a selected city among all the city

In the same way, i'd like to display another text box with the rank of a selected country amo,g all the country.

So the user select a city or a country, and the appropriate text box display the rank.

I suspect to use Set Analysis but I don't know how to set it.

Thanks in advance for any idea

Jean-Jacques