Custom Multi-Currency Excel Bookkeeping Program

I am a self-employed professional (ZZP'er) and had a proficient freelancer create an accounting and administration file for me. It worked perfectly until I purchased a new MacBook. Now, the automatic storage of invoices and the import of bank statements (including Excel files) are no longer functioning. I am looking for a freelancer who can troubleshoot and resolve these issues. Additionally, if successful, I would like to explore the possibility of developing this into an excellent product with installation software for both Mac and Windows. If you are a freelancer with the skills to address these issues and potentially enhance the software, please reach out to discuss further details and collaboration.

The price is negotiable and can be discussed with the developer.