We have found 3 software records in our database eligible for .xls to .xltx file format conversion.
xls to xltx conversion is not so much file export, but the process of making new template (.xltx) based on existing older workbook (.xls), something that can be done simply with Excel or any other spreadsheet editor that supports Excel's formats.
You can find numerous guides and tutorials about Microsoft Excel and how to work with it, including topics about templates. Some are even available on Microsoft Office support website. Of course Excel contains extensive help files that cover this topic as well.
Updated: October 9, 2023
XLS
Files with xls extension are best known as spreadsheets from Microsoft Excel. A spreadsheet is basically a grid of cells sorted in rows and columns. Each cell can contain text, numeric or formula data. Excel XLS spreadsheets can be opened in most other similar programs, such as OpenOffice.org Calc.
XLTX
Files with xltx file extension are spreadsheet templates for latest Microsoft Excel program. These files acts as templates to create similarly looking XLSX workbooks.