Dial *62 to log the extension into all the Queues that the extension is a member of.
... so that implies that the dial code will log you into ALL queues, however, I can't be certain of this as I don't use queues just ring groups and digital receptionists.
This is a 3cx feature, the manual may of the 3CX softward may be found on our download page. It is in the section called dial codes. Please note you may also sing in ot the queues from the managements console, the myphone page and the 3cx assistant.