The external procedure function has no parameters. The input parameter array is already passed through the InitParams() method and stored in the member variable m_pInParamVector. Each entry in the array matches the corresponding IN and IN-OUT ports of the External Procedure transformation, in the same order. The Integration Service fills this vector before calling the dispatch function.
Use the member variable m_pOutParamVector to pass the output row before returning the Dispatch() function.
For the MyExternal Procedure transformation, the external procedure function is the following, where the input parameters are in the member variable m_pInParamVector and the output values are in the member variable m_pOutParamVector: