Functions are not executed remotely on the HC.
If you specify a function to be run on all clients, like so:
[[9], "zam_hc_exclude", true, false] spawn BIS_fnc_MP;
Where zam_hc_exclude is some function defined on all clients and the server, it will run on all clients and the server, except for the HC.
{F19682}
Using the attached mission, export it onto a server, have yourself and the HC join onto the two slots, wait 5 seconds after missions start and then check the RPT log for the server, your client and the HC.
On all machines, the following messages will be logged in the RPT, except for the HC:
"BIS_fnc_MP Test log"
"BIS_fnc_MP Test log"
"BIS_fnc_MP Test log"
"BIS_fnc_MP Test log"
"BIS_fnc_MP Test log"
These messages where created by the BIS_fnc_MP only being run on the server with the following command:
[[[],"log.sqf"],"BIS_fnc_execVM"] spawn BIS_fnc_MP;
Where log.sqf contains:
diag_log "BIS_fnc_MP Test log";
5x.