Variate of Percentrank

Hi,

With the function Percentrank i can get the % position of a number within a list
e.g


$5,000,193,672
$3,453,128,376
$2,233,115,680
$1,115,362,635
$487,910,974
$429,423,144
$370,761,798


$429,423,144 returns 16%

This is fine when you have the numbers in front of you, is there a way a user could type in $410,376,876 and then get the relative position of that number.

Many thanks
Seamus