Use a user defined selection
you can then specify just \\hostname, just \\ipaddress, \\hostname\sharename or \\ipadress\sharename
BTW you do need a remote agent license for share level backups (unless the remote system is running Windows XP.

However if you are using a current version of Backup Exec and have installed and configured the remote agent to advertise/publish to the media server, then your remote server should show up under  Favoorite Recources so you should then not need to manually specify anything at all but just browse to it.