Returns the full path and file name of the document's source file.
[out] A string containing the long name.
[out] A flag that is true if pbstrLongName refers to the original file for the document, false otherwise.
The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.
The method succeeded.
No source file can be created or determined.
This method returns the full path and file name of the document's source file.