This question has been asked and answered numerous times in the past:
Either set the value explicitly as a string, or set a number format mask for the cell that forces display of all digits (e.g. '#,##0' 0r '0') rather than default format.
This is exactly how you would need to do it in Excel itself.
Now please read this thread
that offers some advice on how to resolve these types of problems yourself without needing to ask, and then respect my need for time doing things other than answering the same questions over and over again.