Problems getting PDF file using AX 2009 .Net Business Connector

I have a web page developed using ASP.Net.  The X++ developer wrote a method that I can access using the AX .Net business connector.  The method returns a container.

I am not an X++ developer.  So not sure what a container is in X++.  He also mentioned that the data is bindata.  When I I try to run this method, I get this error:

Unable to open file \\Server123\\Temp\\SS00390.pdf

I really have no idea how to capture the pdf file.  Here is my code presently.  I am using an object variable presently:

object obj;
using (AxaptaObject axObj = axapta1.CreateAxaptaObject("XXXAxSalesPortal"))
{
 obj = axObj.Call("reprintInvoice", testSalesId);
}

It bombs when I run the Call. So my question is, what data type do I used in my C# code to capture the PDF?  Or is there another way to call this method?  Like I said, I'm not an AX guy and I only have a lot experience using the BC.

Thanks!