Join or leave a ring groups

Hi,

Is it possible to join or leave a ring groups, existing and predefined directly from the phone (Aastra 53i) by typing a code on the keyboard (eg *20#)?

The idea being that as part of a hotline people can enter or leave the group easily by typing a code on the phone!

Thank you for your help.

Queue + AddQueueMember + RemoveQueueMember