[World Guard] Limit a plugin to only work in a certain region

I have a plugin that has no permissions that I only want to work in spawn. my spawn is worldguarded and the region is defined as "spawn." can someone please tell me the command, or how to do it in configs? world guard offers no information on this on their wiki from what i can tell. I looked =/

the plugin: It launches a firework into the air above someone who has just logged in. there are no commands for it. I do not want this to work outside of spawn because if someone to log on, it would possibly give away their position. I run a hardcore faction server, and this plugin can ruin somones element of surprise =/

 

*bump*

 

*bump* could someone please help me =/

 

Best recommendation: every time one logs out and logs in should start in spawn LazleCraft does that. Best of Luck! ~Polish