Xlsx to xlw conversion is doable, but not in a sense of spreadsheet conversion. It is the process of creating new workspace based on existing spreadsheet. You can actually do this with Excel and any other software that supports Excel workspace files, but it's not meant as export of data from the spreadsheets.
Updated: August 30, 2023
Unfortunately, there is no detailed software record in the database that match this conversion.
XLSX
Files with xlsx extension are s used by Microsoft Excel for its workbooks (spreadsheets) in Office Open XML format. XLSX is the latest spreadsheet format used by Excel with the adoption of XML formatting first used in Office 2007. While older xls files were in proprietary binary file format, xlsx spreadsheets use a somewhat altered XML scheme.
XLW
Files with xlw file extension generally contain saved workspace for Microsoft Excel programs. These are used by user to save the position to GUI elements and layouts of the screen, so they can use the same settings on different computers.