Can we modify assets in the content browser, with an Editor Utility Widget?

I’ve been looking for a way to changes variables of assets in the content browser (not inside the editor) by script, and I was looking at the Editor Utility Widget feature, but not sure if it’s something I can do.
Practically, I have a quite complex material, with a lot of parameters exposed for my instances, and I was trying to implement a preset feature. The ideal workflow for me would be to choose a preset from a drop-down menu and let a **script **modify some variables with pre-defined values, and save this material.
So far I have troubles to find a way to set values of an asset not loaded in the editor, and I would be really thankful if someone could orient me
Thanks in advance