Putty clients global change hostname

I have a couple hundred clients that use putty to access some Linux servers and I'm looking to change the host name that they are currently using to connect. Originally when it was implemented some clients had IP addresses and others had host names put in and I'm looking to implement a round robin DNS host name so that it will never need to be changed again. Does anyone know of a simple or moderately easy way to implement this type of change? I know that the registry entry for the variable is under current user, but doesn't that change whenever someone else logs in or if that person logs out and then back in again?

Please help,