There are a couple of solutions. This requires a text editor with more features than Notepad, preferably "regular expressions".
1) Get a free download of Notepad++. After pasting your text into a new file window, select Search / Replace from the menu. Put a comma in the "Find what:" box, and the following in the "Replace with:" box: \n
NOTE: You must select the radio button at the bottom left of the replace popup for "Regular expression". The above will execute a regular expression to replace all commas with a carriage return.
2) The same thing can be done with Edit Pad Pro, Ultraedit, etc. Another idea is to view the file in hexadecimal code (Editpad Pro should be able to do this), do a find for the hex value of a comma (2C), and do a "replace all" with the hex value of a carriage return (0D).
Greg Burdett