If you are looking to get a comma separated string into a column with CR LF you wont be able to do that in Notepad++, assuming you didn't want to write code, you could manipulate it in Microsoft Excel.
If you copy your string to location B1:
A2 =LEFT(B1,FIND(",",B1)-1)
B2 =MID(B1,FIND(",",B1)+1,10000)
Select A2 and B2, copy the code to successive cells (by dragging):
A3 =LEFT(B2,FIND(",",B2)-1)
B3 =MID(B2,FIND(",",B2)+1,10000)
When you get #VALUE! in the last cell of column A replace it with the previous rows B value.
In the end your A column will contain the desired text. Copy and past it anywhere you wish.