Thank you very much for your interest in GroupDocs.
Currently it's not possible, however we'll investigate it and maybe we can add clickable regions to the pages from an Excel file where links are specified within a Cell.
If we do manage to implement this the links will have to be shown in the file, not just links and anchor text. We should be able to investigate in the next few days and come back to you with a timeframe if this feature is possible.
In answer to your other question, to modify your pages you should re-upload a new version of the file.
Please feel free to email email@example.com with more questions or future requirements for any of our apps or plugins.
We are very loyal to our customers and where possible we try to implement most sensible and reasonable requests.
With best regards,
GroupDocs Support Team.