Endoscopic Lumbar Discectomy (ELD) is a mini-mally invasive surgical procedure to remove the herniated disc material. In ELD, the clinician employs a hollow endoscope and inserts instruments through a tubular lumen in it to reach the surgical window and perform the discectomy. Some steps, such as the opening of the ligamentum flavum, benefit from the help of an assistant who can replace the surgeon in holding the endoscope while the surgeon is handling the working-tube for the partial resection of the ligament in close vicinity to critical neural structures. This approach has as a disadvantage that it requires two clinicians and is also uncomfortable and non-ergonomic. To overcome this inconvenience, a robotic approach using a collaborative robot to hold the endoscope is explored in this work. The paper describes the development of a collaborative approach starting from the establishment of the surgical requirements, the introduction of a dedicated robotic interface, an initial validation by a surgeon and follow-up experiments with novices. The results show the potential to improve performance and reduce mental load of the new collaborative approach for ELD treatment.