Compare and Copy unique data between 2 workbooks

Hi Experts,

I started working on a macro that needs to compare and copy unique data from selected row between 2 workbooks. The workbooks have identical headers but only one column should be compared *coulmn C (header named: Invoice Number). So, I will have a Master workbook which will be regulary updated (with new invoices), and other workbooks from where the data will copied. A comparison should be made between master.xlsx and new.xlsx, and if the invoice number is not in the Master.xlsx, than the entire row should be copied from the new.xlsx workbook (sheet1 both).

I should put a Button on the Master slide, and when clicking it, the data should be compared and transferred.
Attached I am sending you the both workbooks.

Any ideas? I would really appreciate your help.

Regards,
Pucval