Embedding Excel Worksheets

I have been beating my head against the wall trying to figure out how to do a bulk e-mail with unique file attachments for each addressee. The header and the text is constant, but each manager gets a report for his or her location. I tried embedding the Excel worksheet in a mail merge document, but the recipients could not open the file because they were not connected to our server (the source of the file). If anyone can help,I'd be grateful. Thanks.