May I ask what a RIDER IS on an exclusion

I was reading a post about someone who wanted to get a certain type of surgery but the insurance company was telling them the kind they could have. Then something about talking to the employer about a rider what is a rider if I may ask?

It is like an addition to their contract with the insurance company. Usually an exclusion is in the policy to save money. The company can put a rider on their original contract to now include WLS and then pay the extra. I hope that makes some sense. 

So then is that what I should refer this to be in my letter to the employee. Would I be asking them to please consider placing a rider onto my insurance policy so that they would be able to look at it as an individual policy?

The rider is not just for you. The rider would usually be for the whole company. If you are writing your employer focus on the benefits of the surgery for health and your job-- ie less absences for health reasons and more productive. Also, give them the cost benefits of the surgery vs paying for health problems.