Regex in Zabbix Preprocessing

[Tenou]

Hey there,

I've got a logfile with a lot of lines that I don't want to have recorderd.
Built this regex for that:

/^.*\[RCON Listener #.*\/INFO\]: Thread RCON Client \/127\.0\.0\.1.*$/gm

However, adding it seems to do absolutely nothing. It works perfectly with regular regex, tho. Did I mess up the Syntax for Zabbix?

[Hamardaban]

What type of item? Give an example of log lines.