There is a nice little bookmarket in Github Gist that does the core of what you want -- copying to the clipboard. It does not use any external libraries, which I think of as an advantage.

As written, it copies some static text, but toward the bottom it talks about adapting it to other uses, such as copying the page title.

Since you've stated that 'The extraction is easy enough ...', you should be easily be able to adapt that gist to what you want to do.

I tried the plain vanilla version of the bookmarklet, because I have some static text that I often need to transfer to my clipboard. It works very well in Chrome 61 with no modifications. But make sure you read the comments; some people have suggestions on getting it to work in other browsers and scenarios.

There is a nice little bookmarket in Github Gist that does the core of what you want -- copying to the clipboard. It does not use any external libraries, which I think of as an advantage.

As written, it copies some static text, but toward the bottom it talks about adapting it to other uses, such as copying the page title.

Since you've stated that 'The extraction is easy enough ...', you should be easily be able to adapt that gist to what you want to do.

I tried the plain vanilla version of the bookmarklet, because I have some static text that I often need to transfer to my clipboard. It works very well in Chrome 61 with no modifications. But make sure you read the comments; some people have suggestions on getting it to work in other browsers and scenarios.

Here is the code that I tested, already minified and ready to turn into a bookmarklet:

javascript:!function(a){var b=document.createElement("textarea"),c=document.getSelection();b.textContent=a,document.body.appendChild(b),c.removeAllRanges(),b.select(),document.execCommand("copy"),c.removeAllRanges(),document.body.removeChild(b)}("Text To Copy");

Gist has the pre-minified code as well.