Best way to concatenate

k i’ve got a button that on release generates a random number, then attaches 1 of 4 movieclips in my library all named pos1_mc, pos2_mc, etc.

on (release) {
	var rand = Math.round(Math.random() *3) + 1;

here’s an example of one of my trace statements: pos1_mc,mc,1
but to use attachmovie i know you need quotes in there like this:

How can i get that?