Can I make a URL field value clickable to open a local file on computer?

Generally, regardless of whether you are operating in Ragic or not, browsers do not support this behavior.

However, if you want users to be able to click on a local file path URL stored in a field to open a file on their computer, you can ask them to install a browser extension that enables this functionality. Once installed, you can store a file:// path URL in the field (e.g., D:/_test/A/System_Implementation_Plan.docx), allowing users with the extension to access the file directly.

For example, a related Chrome extension:

Enable Local File Links