How do I set the batch render directory in MEL?

The workspace command controls project-related settings. You can use it to set destination directories for files of type: depth, images, iprImages, lights, renderScenes, sourceImages, and textures.

// This will change the directory where
// batchRender-ed images go:
workspace -renderType "images" "c:/temp";
//Save the change into the workspace.mel afterwards:
workspace -saveWorkspace ;