Yes it is! And it’s a great way!
It is extremely simple to build your own data extraction activity! Please have a look at the documentation here: https://docs.uipath.com/activities/docs/extractor-code-activity-class and try to implement this abstract class as an activity.
To give you a jump-start, we have also built a sample project available on github, that takes care of the entire infrastructure required for building your own extractor: please check out this repo here: https://github.com/UiPath/Document-Processing-Code-Samples .
Long story short, you will only need to put your own algorithm in the activity, and use the existing inputs (original file path, text version, document object model, and list of required fields) to provide the requested output format.
You will find all the documentation you need in the first link