String To Binary
or
Sttring To Hex

Dim Mac(5) As Byte
Dim i As Integer


For i = 0 To Row.MacAddress.Length - 1 Step 2
    Mac(CType(i / 2, Int32)) = Convert.ToByte(Row.MacAddress.Substring(i, 2), 16)
Next
Row.MacAddrBin = Mac