How to setup only one instance behind the amazon ELB

I am wondering if there is a way using amazon interface to have only one machine instance behind the ELB?

If not is there another interface that I can use?

Any suggestion is highly appreciated.

Thanks.

Yes - when you setup your ELB you add the instances you want to put behind it. I'm not sure why you would do this though. ELB will add some latency and if you are pointing DNS records to it you have to use CNAME records (or use Amazon Rout53 which recently added support for alias records). If it is for DNS and you are worried about the IP address changing use an elastic IP address - you get 5 with your account.