How can I make a bot follow a predefined path?

I want my bots to follow a predefine path. How would I do that with a script? After they have reached a certain point they will start automatically attacking, but I’m sure I can make that part myself, I just don’t know how to make it so that they follow a predefined path until that point.

Are you familiar with iTween?

If not, it is a free plugin with great abilities, including some nice path related utilities.
One of the features allows you to attach an object to a path, which is exactly what you want as I understand.

Take a look at the Examples Page, look for the path related examples (there are a few).