Adding App.config in C#, using C# Builder

I am using C# Builder (Personal version). I am trying to add App.config to the project but there is no add-in option as "Application Configuration File". When I add it manually i.e. by adding text file and renaming the text file to App.config, it is shown in the project viewer pane but doesn't load up at runtime (I tested that by using ConfigurationSettings class). Another way around maybe to add the App.config file by using csc.exe (command line) but I don't know what options to use for adding App.config to a specific project (well executable). BTW I don't have VS .Net (I prefer not to have it, I am happy with C# Builder).