Spawning multiple enemies on a path

Can someone give me advice on spawning multiple enemies on a predetermined path, I am in the process of creating a Tower Defense Type game. When the level loads I want to wait a couple of seconds before the enemies start on the path, and I want to create multiple instances of s particular enemies, in different waves

Any help would be beneficial, and or a good resource tutorial on the above

Thanks

I need the same thing! I'm making a zombie survival type game and i need a way to spawn zombies every so often. (note, I have no idea how to use the SED, I'm an uber noob, I do everything through wed using templates and the project manager to assign behaviors to stuff. so if there's no other way then sed, Itd be really helpful if you gave me a little walk through on how to get script working from sed to in game on wed. thanks )

Anybody?

check the AUM magazines.I'm sure theres somthing in there that can help.