Multiplayer - Selected character to Network.guid?

I need to create a script that takes the selected character, at the character selection menu in a multiplayer, and link it to the Network.GUID. So that, for example, when a player sends an RPC to chat that it'll know his character's name and from which server it was sent from.

Something like :

 [RPC]
 void rpc(NetworkMessageInfo info) {
     string username = SelectedChar[info.guid];
 }
 
 //client
 
 void SendRPC(){
    networkview.RPC("rpc", RPCMode.Server, "text that the person sends");
 }