Automate invoice generation from an Excel order sheet. Users should be able to select an order, generate a correctly formatted invoice, save it with a clear filename, and optionally prepare it for email. The solution should include validation and understandable instructions for staff with basic Excel knowledge. The successful freelancer will be expected to work independently, share progress at agreed checkpoints, and raise questions early when a requirement needs clarification. All submitted work should be original, well organized, and ready for practical use after reasonable review.