' Recieves OMR group zones information (e.g.: 0|1|0|0|0) and returns the index of the marked zone (single choice)
' Returns -1 if: no zone is marked (nothing is selected)
' Returns -2 if: more than one zone were selected
' Returns -3 if: at least one uncertain marking is present
Public Function OMRSingleChoiceIndex(omrValues As String, markedZoneChar As String, delimiterChar As String, uncertainChar As String) As Integer

   Dim tmpArray() As String
   Dim i As Integer
   Dim countOfMarkedZones As Integer
   Dim markedIndex As Integer

   ' check for uncertain zones - this is the fastest check possible
   If InStr(omrValues, uncertainChar) <> 0 Then
      OMRSingleChoiceIndex = -3
      Exit Function
   End If

   tmpArray = Split(omrValues, delimiterChar)
   countOfMarkedZones = 0

   For i = 0 To UBound(tmpArray)
      ' count each marked zone and store last marked position
      If tmpArray(i) = markedZoneChar Then
         countOfMarkedZones += 1
         markedIndex = i
      End If
   Next

   OMRSingleChoiceIndex = markedIndex
   If countOfMarkedZones = 0 Then OMRSingleChoiceIndex = -1
   If countOfMarkedZones > 1 Then OMRSingleChoiceIndex = -2


End Function