Sorokin,
What version of BW are you on ...? the document you have linked for the how to is very very old - it still will work but then it might become failry complex if you want to implement the same thing.
Instead - have a look at web service datasources for BW and you can use the WSDL for the same to load data into BW and the solution would be more elegant. Web Service datasources would be available starting BW 7.x.