I'm not sure you can do this with XLSB. XLSX and XLSM are basically the same - XML-based files. XLSB is a binary format, which is closer to the old XLS format than anything else. Simply changing XLSB to XLSX will not work. You could try changing it to XLS and try to connect to the file that way but, I suspect this won't work either. I'm afraid that you'll probably need to use a script task to programatically open the file in Excel and save it in a different format.