if you know the code for your key you can insert the code manually by using the procedure laid down in the renault laguna owners manual this will allow you to bypass the immobaliser and run the car in the old fashion way(lock and start with a key) but this is no use to you unless you have the code but that said you should be able to get your code from the renault dealers by giveing them your engine and vin numbers
m treadwell, January 2005