According to the excel documentation, pressing alt+enter causes char to appear (10). Because char(10) is a Line-Feed (LF) character, it is the same as n in Java.
The typewriter movements of dragging the page carriage back to the start and scrolling it up a line are designated r (CR) and n (LF).
In Excel, Alt+Enter corresponds to CR+LF in Windows Format. We may check by pasting the appropriate text into Notepad++ from an Excel cell that contains Alt+Enter (check the below snapshot)
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In Excel, Alt+Enter is a Line Break character that works in the same way as Chr (10)