From http://www.w3schools.com (Copyright Refsnes Data)

WMLScript elementAt() Function

The elementAt() function divides a string into elements and returns the element at the specified index position.

Syntax

n = String.elementAt(string, index, separator)

Part	Description
n	The string returned from the function
string	The string to be parsed
index	An integer defining the part to be returned
separator	The separator that divides the strings

Example

NOTE: If index is negative, the first element is returned. If index is too high, the last element is returned.

var a= String.elementAt("Visit W3Schools today",0," ");
var b= String.elementAt("Visit W3Schools today",1," ");
var c= String.elementAt("Visit W3Schools today",2," ");
var d= String.elementAt("Apples+Bananas",0,"+");
var e= String.elementAt("Apples+Bananas",1,"+");
var f= String.elementAt("Apples+Bananas",5,"+");

Result

a = "Visit"
b = "W3Schools"
c = "today"
d = "Apples"
e = "Bananas"
f = "Bananas"

Complete WMLScript String Library