Experience on tax exemption for F-1 visa holders?

Hi Elphas!I'm managing the HR for the team at ReJoule. We have one employee on an F-1 visa and from France and we just learned there's some special tax exemptions -- but one year after we've already been deducting the funds. It sounds like the most expedient way for the employee to get the funds back is through the company while the IRS will reimburse us. I'm looking for anyone familiar with this process. I want the employee to get their money back but want to make sure its not too long before we get reimbursed. We're an early stage startup so I'm very closely managing cash.Any advice on this would be super helpful!