Overwrite elements when fetching lots of dois

[zerothi]

Fetching the bib from the doi is simply amazing.

However, in certain situations it might be beneficial to overwrite certain things in the bib.
For instance, it might be nice to add certain tags to the bib-tex file, or to overwrite the reference key.

I would like something like this:

10.1234/12039c key=MyRefKy segment=Chapter1
10.1234/12039d key=HelloWorldExample segment=Chapter2