Replaceable Tabs?

I just had an idea, that it would be nice to have a replaceable tabs system,lets say you open a lot of tabs but want a link to open in an open tab, you could just put a "Lock" on the tab so everytime you do ctrl+Middle click on a link its opened in the locked tab.
I don't have that much knowledge about programming or building something like this, so this is just my idea
Greetings, Firefox is great