Cymbidium with no leaves and rotted roots.

[Nic]

This is my first orchid. I inherited a Cymbidium last year when a friend passed away so it has sentiment attached to it. It had great leaves for a while, then I was told it was not getting enough sun and to put it outside and leave it, which I wish I had never done now. It has now lost all its leaves and today I was going to 'sphag and bag' it as I had found that on various sites but all the roots are rotted. I am not sure if that is the right thing to do. It is really not well but I don't want to give up on it. Can anyone give me some advice?