Welcome to the Forum, K-Com.
Using Defense+, you can allow any application to run as 'Trusted'. This is only concerning its actions on your computer.
The firewall is the module that restricts or limits actions outside your computer.
Assuming your application has run, it will have a rule in Defense+ To make sure this is 'Trusted', go to Defense+/Advanced/Computer Security Policy, and locate your application. If it is not already listed as 'Trusted', select it and click 'Edit'. Select 'Use Predefined Policy', and from the drop down, select 'Trusted'. Click 'Apply' and click 'Apply' again.
Your application is now a trusted application to run on your computer with full access to your system.
To prevent it from accessing the Internet, select Firewall/Advanced/Network Security Policy.
If your application is already listed, follow the same procedure above, but select 'Blocked' for your choice. If it isn't listed, you can click 'Add' to include it in the list.
When you run your program, if it wants to access the Internet, your firewall will alert you. Select 'Blocked' and check the box 'Remember my answer'.
This will prevent the program from any Internet access.