%mcm
From Zenitel Wiki
The %mcm macro is related to the Multiconference feature. The macro will return the physical number of the Mix Controller associated to the Mixer Channel.
Syntax
%mcm(Mix Channel phys no)
Examples
%rphy(101) - Return physical number 1 in a default database %rphy(%1.dir) - Return physical number of the event Owner %rphy(%2.dir) - Return physical number of the Related To station