Calculo do CRC

Bom dia pessoal, convertir essa função do C# para vba ele funciona perfeitamento no excel e accessporem estou tentendo usar ela no vb.net  editor VISUAL STUDIO 2013, aparece o erro conforme a imagem enexo, alguem consegue corrigir esse erro;Function crc_ccitt_ffff(strParam As String) As String        Const CRC_POLY_CCITT As Long = &H1021&        Const CRC_START_CCITT_FFFF As Long = &HFFFF&        Dim crc As Long, b() As Byte, c As Long, i As Long, j As Long        Dim crc_tabccitt(0 To 255) As Long        For i = 0 To 255            crc = 0            c = i 256            For j = 0 To 7                If (crc Xor c) And 32768 Then                    crc = (crc 2) Xor CRC_POLY_CCITT                Else                    crc = crc 2                End If                c = c 2            Next j            crc_tabccitt(i) = crc        Next i            b = strParam        crc = CRC_START_CCITT_FFFF        For i = 0 To UBound(b) Step 2            crc = (crc 256) Xor crc_tabccitt(((crc \ 256) Xor b(i)) And 255)            crc = ((crc \ 65536) 65536) Xor crc        Next i        crc_ccitt_ffff = Hex(crc)    End Function