BizTalk 2010 : Sample pipeline with filename extraction

public IBaseMessage Execute(IPipelineContext pContext, IBaseMessage pInMsg)
{
    VirtualStream inboundStream = new VirtualStream(pInMsg.BodyPart.GetOriginalDataStream());
    VirtualStream outboundStream = new VirtualStream(VirtualStream.MemoryFlag.AutoOverFlowToDisk);

    string sBatchName = Path.GetFileNameWithoutExtension(pInMsg.Context.Read("ReceivedFileName", "http://schemas.microsoft.com/BizTalk/2003/file-properties").ToString());

    AccountingEntriesExcelCreator ExcelCreator = new AccountingEntriesExcelCreator();
    outboundStream = ExcelCreator.CreateExcel(inboundStream, sBatchName);
    if (outboundStream != null)
    {
        if (outboundStream.Length > 0)
        {
            outboundStream.Position = 0;
            pInMsg.BodyPart.Data = outboundStream;

            pContext.ResourceTracker.AddResource(inboundStream);
            pContext.ResourceTracker.AddResource(outboundStream);
        }
        else
        {
            pInMsg = null;
        }
    }
    else
    {
        pInMsg = null;
    }
    return pInMsg;
}