Excel spreadsheets, getfile(), and the GP2013 Web Client

Would anyone know if the dexterity code to read an excel spreadsheet is the same as doing it in the full client install? When I select the file to read using dexterity's getfile() function, GP automatically changes the path to the file to something like

"C:\fake\1\spreadsheet.xlsx". (There is no directory called "fake" -- I'm not sure where GP gets that from).

The code I have works just fine when executed from within the full GP2013 client, but the Web Client throws an exception at the last line of this block of code:

     local reference xlApp;

     try

        xlApp = COM_CreateObject("Excel.Application");

        workBook = xlApp.Workbooks.Open(Path_MakeNative(l_GenericPath));

        ...

The Exception_Class() is "EXCEPTION_CLASS_OBJECT_EXCEPTION".

It seems like the COM object is not able to locate the file at that "fake" path, and that is why it throws an exception?

Thanks in advance.