Risolto
codice:
string altChunkId = "AltChunkId1";
MainDocumentPart mainPart = document.MainDocumentPart;
AlternativeFormatImportPart chunk = mainPart.AddAlternativeFormatImportPart(
AlternativeFormatImportPartType.WordprocessingML, altChunkId);
using (FileStream fileStream = File.Open("embed.docx", FileMode.Open))
{
chunk.FeedData(fileStream);
}
AltChunk altChunk = new AltChunk();
altChunk.Id = altChunkId;
body1.InsertAfter(altChunk, body1.Elements<DocumentFormat.OpenXml.Wordprocessing.Paragraph>().Last());