Metal hose that goes from engine to back of van leaks water on 1993 Ford E-150

This is a 93 ford conversion turtle top van. There is a metal hose that goes from the engine to the back of the van it is all rusted out and needs to be replaced. Does anyone know what the purpose of this hose is? What its called and where I can get one? It leaks water when the Van is running. Thanks

Asked by for the 1993 Ford E-150
It is the supply line for the rear heater core at the rear of the van.Should be replaced or rerouted out of service,this van probably has 2 heater cores.
Thanks a lot for your advice. Do you know if there is a way to remove the supply line and plug the hole or do I have to reroute it some other way?