var util = m_Map.GetUtility();
 
var FullPath = util.ExpandFileName("poi.png");

alert("Image FullPath = " +  FullPath);

#include "CXUtility.h"

CXUtility util = m_Map.GetUtility();
CString FullPath = util.ExpandFileName(_T("poi.png"));
AfxMessageBox(FullPath);