Any document or spreadsheet file (including the .sxc file from early OpenOffice.org) can be exported and saved as a PDF document. This can be typically done using default PDF export function or via a virtual PDFprinter, so for .sxc files (old OpenOffice spreadsheets) your best hope for sxc to pdf conversion is one of the successor products Apache OpenOffice/LibreOffice Calc.
Updated: November 4, 2022