use analogue I/O to control LED

I am working on a project building a light organ for an upcoming performance. The original design used 12 digital I/O to control the 12 LED's - which represented 1 octave. However, we have decided to introduce a 13th note - which will be triggered at the very end and for this I was hoping to use one of my analogue I/O, however I am having trouble figuring out how to turn it on.
To turn on my digital I/O pins I use:
pinMode(13, OUTPUT);

I have looked online and can't seem to find the appropriate code for defining the analogue pin as an output.

many thanks for your help

You can use the analog pins as if they were digital outs.

I think you just use pin numbers 14 - 19 in stead of the usual analog 0 - 5 pin numbers.

thanks for that - exactly what I needed.