Assuming the iPod is running IOS you should be able to use the iPhone configurator from the app store. It's usually used for mass configuring iPads or iPhones, but will likely work with an iPod too.
If you click Prepare > Setup > Certificates > Configure Settings > Configure
You can then choose PKCS1 or PKCS12 formatted certificates to install.
If you navigate back to the Settings tab on the main screen, you should be able to install the profiles with Install Profiles... or Prepare.
Installation is done with a USB cable, which satisfies your no internet requirement.