If you add a network to the connect dialog then you can use that same network in the Perform section, therefore, being able to use perform for individual networks which are not already listed in servers.ini.
To do so,
ALT+O > Connect > Servers > Add - Fill out the necessary boxes. For further help, click the 'Help' button in the add server dialog. Once it is successfully added, you should be able to go to the Perform section and click on 'Add' again - now with the network you added listed in the drop down menu
G'luck.
Regards,
