It does not seem likely to use a document spreadsheet, such as .stw files from older OpenOffice.org, for making new spreadsheets in Microsoft Excel format (.xls, .xlsx). You need a spreadsheet template, not a document template if you want to create spreadsheet based on predefined settings.
Found 2 different conversion types using the same filename extensions.
Conversion stw to xlsx type 1:
Convert from OpenOffice.org text document template to Microsoft Excel Open XML workbook and spreadsheet.
Unfortunately, there is no detailed software record in the database that match this conversion.