Won't write to Excel

I've been trying to perform the complete steps associated to this documentation and can't get the update to Excel to work:  http://docs.telerik.com/teststudio/advanced-topics/coded-samples/general/write-into-data-source 

I have added a reference to this path\file:  C:\Program Files (x86)\Microsoft Visual Studio 11.0\Visual Studio Tools for Office\PIA\Office14\Microsoft.Office.Interop.Excel.dll

as described here:  http://docs.telerik.com/teststudio/advanced-topics/coded-steps/add-assembly-reference Please see the attached jpg file to see the error.​

What am I doing wrong?

Here is a copy of the pertainent entries from the Log file:

'6/19/2015 1:04:40 PM' - Using 'InternetExplorer' version '11.0' as default browser.
'6/19/2015 1:04:41 PM' - 'Pass' : 1. Navigate to : 'http://www.checkdomain.com/'
'6/19/2015 1:04:41 PM' - 'Pass' : 2. Enter text 'www.ask.com' in 'DomainText'
'6/19/2015 1:04:42 PM' - 'Pass' : 3. Click 'Submit'
'6/19/2015 1:04:42 PM' - LOG: 1
'6/19/2015 1:04:42 PM' - LOG: 2
'6/19/2015 1:04:42 PM' - LOG: 3
'6/19/2015 1:04:43 PM' - LOG: 4
'6/19/2015 1:04:43 PM' - LOG: 5
'6/19/2015 1:04:43 PM' - LOG: 6
'6/19/2015 1:04:44 PM' - 'Pass' : 4. [AddToExcelFile_CodedStep] : New Coded Step