Description:
This function will return the external Id (XID) of the specified
Document. The external Id is the (absolute) path of the initial file
that contained the text which was used in order to create the specified
Document. The returned value will be encoded using the UTF-8 encoding
(thus enabling the existance of non Latin characters in the value). The return value will be of type string.
Notes:
This function is equivelant to CDM_GetExternalId (C++ API).
Generated by: petasis@aias on Wed Aug 16 10:31:45 PM EEST 2006.