Transferring Data from one Workbook to Another based on whether or not the cell is empty

Hi Guys,

I got an excel workbook with information that I transferred from Microsoft Access. The information is located on the Export Sheet of a master workbook. Now I want to export the data to a second sheet called Master on another pre-existing workbook (Tax Numbers) without replacing the old information. The data that I want to transfer should be based on the condition of whether or not the information is filled in column M. Any ideas or pre-existing vba codes that I can use? Hope this makes sense