Writing a script to delete certain layers, one of them being the active layer when the drawing opens up. Is there a command to change layers?

I work in a lot of the same types of drawings. I have a script that deletes 3 layers, I'd love to be able to delete a 4th but any time the drawing opens, that is the active layer. In order to automate this, I don't want to have to manually change the active layer but that is a workaround. Any ideas on how to change the active layer in a script? I've tried ACTIVELAYER but I can't figure that out. Doesn't let me just type in the layer name to make it active.