The Visual Basic PdhGetCounterPathFromList function copies the counter path referenced by the Index parameter from a counter path list created by the user from the most recent call to the PdhCreateCounterPathList function.
PdhGetCounterPathFromList(
  ByVal Index as Long,      
  ByVal Buffer as String,   
  ByVal BufferLength as Long)   
as Long
 The function returns the number of characters copied to Buffer.
Performance Data Helper Overview, Performance Data Functions