I have a document that is in xlsx format and I need to keep in that format. I am trying to make a change to a column of cells. (Hi lite column, format cell> change leading zeros to 6 or change type to text.) I then save the document(have it set to not ask me about saving in ODF format so it will keep its xlsx format. When I reopen the document, the column format has reverted back to leading zeros ‘1’. How do I force it to keep the change I am making?