Enhance Content datasource

Hi experts

I need to extend BW content transaction datasource.

The extract structure already has the wanted field through an include.

The relevant CMOD for transaction data is EXIT_SAPLRSAP_001.

How do we get the field into the datasource?

Is the coding at the last screen of this blog sufficient?

http://scn.sap.com/blogs/VijayS/2013/09/30/extending-extractor-datasource-to-include-custom-fields

Thanks

T.