To simplyfie bentleybob's suggestion you can have a look at this add-in: http://www.mrexcel.com/chal/pareto.zip
All of the formulas in B are =RAND() functions. Click the checkbox to recalc, and a whole series of dynamic range names cause the chart to redisplay sorted values.
It also make it possible to place the forulas for sorting the data in a defined name so youre WB will look like it is a built in function.
It is a beta version of a projekt that i never continued to develop. so it doesent look very good but it does what it should. The add-in also allows
to create a calculated datatable that sorts the data as well as aoutomated creation of paretochart.