Coolant leak on SAAB NG900

[Garett]

Today I parked up and noticed a small pool forming under the car, which on closer inspection turned out to be engine coolant. So a question to anyone who knows these motors, there's a thin pipe running from the top of the expansion tank to the top of the radiator, at the point where this pipe joins to the radiator is a plastic piece on the radiator which the pipe is held onto with a jubilee clip. This piece of plastic has deteriorated and become very soft and brittle and has snapped so the pipe has only a very small piece of radiator to hold onto.

Any suggestions on how I can fix this, the rad has plastic mouldings either side of the radiator which seem to be integral to the rad itself.
I don't really want to have to replace the radiator!
I assume the pipe carries water from the radiator back into expansion tank? Could I block the hole as a temporary measure to stop fluid loss?

Any suggestions?

Thanks