Performing a Secret nikaah and thereafter re-performing the nikaah

My daughter received a wedding proposal. We have accepted, but the problem is the boy can only marry her when he has completed his studies [1 year's time]. The kids want to see one another. Can we have a contractual nikkah now, no hankie pankie, but just spend time in parents presence, then when he can earn a living have another nikkah and they can now live as man and wife Insha Allah. What can you advise mufti. We don't want the kids to do zinnah/fitna and we understand that the boy wants to finish his studies, both sides of the parents can't afford to maintain the new couple now. Please advise.