Function Azalea_EAN13(ByVal EAN As String) As String
' UPCTools 
' Copyright 2016 Azalea Software, Inc. All rights reserved. www.azaleabarcodes.com

' Creating an EAN-13 in Excel 2003
' Your input, EAN, is a string consisting of a 12-digit number.

  Dim checkDigitSubtotal As Integer     ' a check digit subtotal
  Dim checkDigit As String              ' the check digit itself
  Dim temp As String                    ' a temporary placeholder
  
  ' Calculate the EAN-13 check digit.
  checkDigitSubtotal = 3 * (Val(Mid(EAN, 2, 1)) + Val(Mid(EAN, 4, 1)) + Val(Mid(EAN, 6, 1)) + Val(Mid(EAN, 8, 1)) + Val(Mid(EAN, 10, 1)) + Val(Right(EAN, 1)))
  checkDigitSubtotal = checkDigitSubtotal + Val(Left(EAN, 1)) + Val(Mid(EAN, 3, 1)) + Val(Mid(EAN, 5, 1)) + Val(Mid(EAN, 7, 1)) + Val(Mid(EAN, 9, 1)) + Val(Mid(EAN, 11, 1))
  checkDigit = Right(Str(300 - checkDigitSubtotal), 1)
   
  ' Begin building the output string with the 1st character's human-readable, L guard bars & odd parity of 1st digit
  temp = Chr(194 + CInt(Left(EAN, 1))) & "x" & OddBar(Mid(EAN, 2, 1))
   
  ' Build the remainder of left half of symbol's parity is based on 1st digit
  Select Case Left(EAN, 1)
    Case "0"  ' OOOOO
      temp = temp + OddBar(Mid(EAN, 3, 1))
      temp = temp + OddBar(Mid(EAN, 4, 1))
      temp = temp + OddBar(Mid(EAN, 5, 1))
      temp = temp + OddBar(Mid(EAN, 6, 1))
      temp = temp + OddBar(Mid(EAN, 7, 1))
    Case "1"  ' OEOEE
      temp = temp + OddBar(Mid(EAN, 3, 1))
      temp = temp + EvenBar(Mid(EAN, 4, 1))
      temp = temp + OddBar(Mid(EAN, 5, 1))
      temp = temp + EvenBar(Mid(EAN, 6, 1))
      temp = temp + EvenBar(Mid(EAN, 7, 1))
    Case "2"  ' OEEOE
      temp = temp + OddBar(Mid(EAN, 3, 1))
      temp = temp + EvenBar(Mid(EAN, 4, 1))
      temp = temp + EvenBar(Mid(EAN, 5, 1))
      temp = temp + OddBar(Mid(EAN, 6, 1))
      temp = temp + EvenBar(Mid(EAN, 7, 1))
    Case "3"  ' OEEEO
      temp = temp + OddBar(Mid(EAN, 3, 1))
      temp = temp + EvenBar(Mid(EAN, 4, 1))
      temp = temp + EvenBar(Mid(EAN, 5, 1))
      temp = temp + EvenBar(Mid(EAN, 6, 1))
      temp = temp + OddBar(Mid(EAN, 7, 1))
    Case "4"  ' EOOEE
      temp = temp + EvenBar(Mid(EAN, 3, 1))
      temp = temp + OddBar(Mid(EAN, 4, 1))
      temp = temp + OddBar(Mid(EAN, 5, 1))
      temp = temp + EvenBar(Mid(EAN, 6, 1))
      temp = temp + EvenBar(Mid(EAN, 7, 1))
    Case "5"  ' EEOOE
      temp = temp + EvenBar(Mid(EAN, 3, 1))
      temp = temp + EvenBar(Mid(EAN, 4, 1))
      temp = temp + OddBar(Mid(EAN, 5, 1))
      temp = temp + OddBar(Mid(EAN, 6, 1))
      temp = temp + EvenBar(Mid(EAN, 7, 1))
    Case "6"  ' EEEOO
      temp = temp + EvenBar(Mid(EAN, 3, 1))
      temp = temp + EvenBar(Mid(EAN, 4, 1))
      temp = temp + EvenBar(Mid(EAN, 5, 1))
      temp = temp + OddBar(Mid(EAN, 6, 1))
      temp = temp + OddBar(Mid(EAN, 7, 1))
    Case "7"  ' EOEOE
      temp = temp + EvenBar(Mid(EAN, 3, 1))
      temp = temp + OddBar(Mid(EAN, 4, 1))
      temp = temp + EvenBar(Mid(EAN, 5, 1))
      temp = temp + OddBar(Mid(EAN, 6, 1))
      temp = temp + EvenBar(Mid(EAN, 7, 1))
    Case "8"  ' EOEEO
      temp = temp + EvenBar(Mid(EAN, 3, 1))
      temp = temp + OddBar(Mid(EAN, 4, 1))
      temp = temp + EvenBar(Mid(EAN, 5, 1))
      temp = temp + EvenBar(Mid(EAN, 6, 1))
      temp = temp + OddBar(Mid(EAN, 7, 1))
    Case "9"  ' EEOEO
      temp = temp + EvenBar(Mid(EAN, 3, 1))
      temp = temp + EvenBar(Mid(EAN, 4, 1))
      temp = temp + OddBar(Mid(EAN, 5, 1))
      temp = temp + EvenBar(Mid(EAN, 6, 1))
      temp = temp + OddBar(Mid(EAN, 7, 1))
  End Select
 
  ' Add the center guard bars & the build right half of symbol using set C (0-9)
  Azalea_EAN13 = temp + "y" + Mid(EAN, 8, 5) + checkDigit + "z"
 
  ' The output, Azalea_EAN13, needs to be formatted in one of Azalea Software's UPC fonts.
  ' We recommend UPCTallThin at 73 points.

  ' Excel: B1=Azalea_EAN13(A1)
  ' Or put another way, yourContainer.text=Azalea_EAN13(yourInputString)
  

End Function
 
Private Static Function OddBar(ByVal theString As String) As String
' UPCTools 16may12 jwhiting
' Copyright 2012 Azalea Software, Inc. All rights reserved. www.azaleabarcodes.com
  OddBar = Chr(65 + (Val(theString)))
End Function
 
Private Static Function EvenBar(ByVal theString As String) As String
' UPCTools 16may12 jwhiting
' Copyright 2012 Azalea Software, Inc. All rights reserved. www.azaleabarcodes.com
  EvenBar = Chr(75 + Val(theString))
End Function