如何在不创建损坏文件的情况下插入Excel单元格?

I'm using the OpenXML SDK to update the contents of an Excel spreadsheet. When inserting cells into an Excel row they must be inserted in the correct order or the file will not open properly in Excel. I'm using the following code to find the first cell that will be after the cell I am inserting. This code comes almost directly from the I'm using the OpenXML SDK to update the content