use HtmlFixedSaveOptions.PageIndex and HtmlFixedSaveOptions.PageCount properties to export a single page to HTML format as follows:
Document doc = new Document("D:\jason\testDemo.docx");
HtmlFixedSaveOptions fixedOption = new HtmlFixedSaveOptions();
fixedOption.setPageIndex(0);
fixedOption.setPageCount(1);
fixedOption.setPrettyFormat(true);
fixedOption.setExportEmbeddedCss(true);
fixedOption.setExportEmbeddedFonts(true);
fixedOption.setPrettyFormat(true);
fixedOption.setUseHighQualityRendering(true);
fixedOption.setSaveFormat(SaveFormat.HTML_FIXED);
doc.save("D:\jason\testDemo.html", fixedOption);
Aspose.HTML Web Applications 将 HTML 转换为 DOCX
https://products.aspose.app/html/zh/conversion/html-to-docx