At present if you are in a particular endnote and wish to cross reference to another endnote, it is impossible to to obtain the new endnote number. While the list of endnotes shows the endnote number, it is not an option to choose just the number. So yo only get the full text of the endnote. This is different from cross referencing, say, a list of Figures where you can cross reference just the Figure and the figure number. Fo some reason the endnote number simply does not exist as a Paragraph Number