Thank you @AnnieRuru for the source.. I implemented this in my server.. no compiled error, no failed . but no file built in conf/import folder.. it said no file "conf/import/OnPCUseSkillEvent.txt" instead of "OnPCUseSkillEvent.conf" when in your post is conf formatted file.
And i dunno what should i do with OnPCUseSkillEvent.txt or .conf .. can anyone help me? Thank you ^^