Just for the record 'Normal.xlsm' is not a template. See Change the default file format for saving workbooks . It is a macro-enable Excel workbook format.

Also I don't see how anyone could edit the MS 'Excel.exe' file to force it to use the Normal.dotm Word template. Excel uses the templates 'Book.xltx' and 'Sheet.xltx' stored in the XLSTART folder when it launches.

It would be interesting to see if @Windspeed finds a solution and what it was. Are you watching OP?