Problem with off line charts

 

Hi I'm writing an expert that runs on M2 off line chart.
Now I'm trying to recall a double from M3 off line chart, but it doesn't work.

I would expect to write the following

iCustom(NULL,PERIOD_M3,"Pippo",0,0)

but I don't find "PERIOD_M3" in the choice window.

How can I solve?
Thank you!