It's possible to create a collage in the print module using a custom template. And then you can output that to a JPEG rather than to your printer. But in reality, it's easier to do that kind of work with Photoshop or Photoshop Elements.
sorry to but in but it interest me too (the question) where would you get the template for Light room or is there a template in photoshop/photoshop elements? Sorry Im new to all this.