I need to find a way to have a macro execute ONLY if another workbook is opened. I export data from another source and it creates an Excel workbook. I would like a macro to trigger when it sees this workbook open (if that's possible). This macro would then go on to copy specific data from the workbook into the workbook I already have open (the workbook containing the macro). I need this to trigger multiple times. Only my workbook and the workbook that is opened from the data source would be open at any one time (so only 2 workbooks open at any given time). Once I've obtained the information I close the data source workbook and go back and do it all over again.

I'm working in Excel 2013.