RibbonX XML: How can I put in a carriage return or new line within " " marks

In a screentip I want to separate two paragraphs of text by a empty line.
To do that I need to add a new line or a couple CRs. How do I do that?

Example:
screentip="Hi, how are you doing. Thank you I am fine."

The above line gives me:
Hi, how are you doing. Thank you I am fine.

What I want is:
Hi, how are you doing.

Thank you I am fine.