XI Header Line into a XML File with message mapping

I'm making a Message Mapping, and in the source i have one line with three Columns.

This is an example of the line docitmMsg with the three columns called doctype, rate DataVersion.

</ns2:docitmMsg>doctype rate="1.00" DataVersion="1.05"</ns2:docitmMsg>

I need to know With format I have to use to create that.

Any help and suggestions will be welcome.

regards,

Fernando