Export XML lines without header

Hi!, I'm using an XMLPort to generate an XML but I need generate an XML like this: (repeating error without header):

<Response>
<Errors>
<Line Number=1>
<Comment>comment</Comment>
<Error>Error x</Error>
<Error>Error y</Error>
<Error>Error z</Error>
</Linea>
<Line Number=2>
<Comment>comment</Comment>
<Error>Error x</Error>
</Linea>
</Errors>
</Response>

Now I generate a similar XML but each "error" is inside his own header:
<Error><Message>Error x</Message></Error>
<Error><Message>Error x</Message></Error>

And I don'l like use "Attribute" .
Thansk