Is there are script for what I need?

I have to make a zombie spawn system is there anyway that there is a script for this? It's for a game that I am making but I'm trying to make a zombie spawn system. (Basically They will crawl through the window . My only concern is to make the spawn system. I have a screen shot of it if you want me to show you.

               -Best Regards Savion
                                                                                                                 

Not all scripts are made equal

You're too specific. Step back, think about what you're asking, and we'll point you in the right direction.