can't paste using clipboard program's shortcuts

Hello, I am trying to paste pre-saved text into text forms in Firefox and the programs I have tried are not working in Firefox although they work in Chrome. I can use CTRL+V in Firefox but this only copies an item currently on the clipboard; a program like QuickTextPaste allows me to use multiple shortcuts to paste different texts using my own shortcuts like "L Windows key + F4". I can use QuickTextPaste in Chrome using the same shortcut in the same text form fields but not in Firefox. Is there any way that I can enable this in Firefox? I read something about security settings and altering the .js file but I wonder if that will really help. I have also searched Firefox extensions to see if something has already been created that will do the same thing as QuickTextPaste, but the ones I looked at do not seem to be updated to FF 31. For example, Paste Email Plus worked when I opened it, but as soon as I saved text to it and set a default, now it only has a tiny box in the context menu and I can't even reopen the program to make changes. It seems very broken. I am using Windows 7 64 Enterprise and FF says that 31 is "up to date". Thank you so much for any advice.