In certain versions of excel, CSV files may display with additional characters in the first cell of the document.
Open the document in a Text Editor to verify that the extra characters do not exist in the file. If they do not, either save the file as a different type or use a different program to view the spreadsheet.
To avoid the display issues of the CSV file exported from a list, select Export HTML. This will provide you with an XLS document you will be able to manipulate in Excel.