Hi,
Searching the site using "Search operators"
site:scn.sap.com multi line cell in excel
Does produce some results but unfortunately not a full working program (I might be wrong on this one 
) .
Also reading https://en.wikipedia.org/wiki/Comma-separated_values I noticed this example:
Based on this article I wrote program Y_R_EITAN_TEST_10_10 (attached) .
General description
The program create CSV string based on internal table input .
The program create HTML string based on internal table input .
The program also create a multi line cell (follow FORM get_long_text) .
Both strings are sent as mail attachments .
Technical
Local helper classes:
CL_CSV - help to create a valid CSV string (I hope I did not miss something....
) .
CL_HTM - help to create HTML string .
The program use CL_BCS to send the mail .
Output
Attachment_CSV.csv as it appears in Excel (you have to play with the row height.....)
Attachment_HTM as it appears in the browser (IE)
Attachment_CSV.csv as it appears in LibreOffice (The row height is done automatically 
)
