Inserting a character into a string

programming flash
1

There seems to be a lack of these kinds of topics on Google, so here I am!

Anywho, I need to insert a character at specific areas of a string, but when I use to following code:

var test:String = "1,1,2,2,3,3";
trace(test.replace(test.slice(5,5), "%N"));

this is the output:

%N1,1,2,2,3,3

This strikes me as odd. Shouldn’t it be “1,1,2%N2,3,3” instead? Obviously, I’ve done something wrong along the way, but I’m not sure what I’ve done wrong or how to fix it.

Help! Thanks. :}