Clip and Paste function not working with Firefox and Blackboard

I need instructions on where and how to place a user.js file so that my portable apps firefox browser and Zotero can interact with the Blackboard we are using in my seminar this semester.

How do I construct the file and where do I place it? I assume it follows the model:

user_pref("capability.policy.policynames", "allowclipboard");
user_pref("capability.policy.allowclipboard.sites", "http://bboard.mcckc.edu");
user_pref("capability.policy.allowclipboard.Clipboard.cutcopy", "allAccess");
user_pref("capability.policy.allowclipboard.Clipboard.paste", "allAccess");

but I cannot determine where to find the .js file or more accurately where to place it when Firefox is functioning from a USB Flashdrive.