I have an array of x,y points which are inputted in a single cell
for example
array 1 = (0.2,0.4) , (0.23,0.34),(.87,.32),(-.33,-.54).... there are such 50 points in array 1.

There are different numeric triggers which are matched with the arrays.
For example
trigger 1 = array 1
trigger 2 = array 2
so on...

When the event trigger 1 = array 1 is true then I want to read these 50 points in array 1 and randomly pick one set of (x,y) and write the value in a different cell. How to do that in excel ?