Steps to reproduce:

1. AllowKey=system.run[[powershell -command "dir *"]] on Windows agent side
2. Keys system.run[[powershell -command "dir C:\,C:\Backup"]] and  system.run[[powershell command "dir \{$PATH}"]] for host elements

Result:
system.run[[powershell -command "dir C:\,C:\Backup"]] ** works like a charm, but if I use macro {$PATH}=C:\,C:\Backup then Zabbix says "Unsupported item key"
Expected:
Macro baehavior should act the same as plain key.