How to extract comment in a specific format

[Jason Li Ting Chung]

Hi Community,

I can extract comments from the following script in listener:

<%
def commentManager = com.atlassian.jira.component.ComponentAccessor.getCommentManager()
def comments = commentManager.getComments(issue)
for(comment in comments){
out << "Comment by: " + comment.getAuthorApplicationUser().getDisplayName() +"\n"
out << comment.body + "\n"
}
%>

The format is as per attachement.

But I need to extract only the external comment only but with the same format

What addition do I need to add to script to perform the required functionality?

Best regards,
Jason Li