Connecting to an SAP Business Warehouse 30b using IS 46

I would like to connect to a SAP BW 3.0 with the Integrationserver to load data of a non SAP system into it. Is there a possibility to do this with the normal SAP adapter? Has anyone done this before and has information on how to do this.
We are using webMethods 4.6 at the moment but will upgrade to version 6 soon.

Thanks a lot