If you need a way to add a new line between lines, this will work:
(define s (string-append "exa " "\n" " mple"))
s
=> "exa \n mple"
(display s)
=> exa
mple
In the above snippet, I use string-appendto combine two lines with a new line in the middle. As a result, the line swill have a new line between them when using it, for example, by displaying it.
, "exa \n mple", , , , , , ..