Edit CSV files present in document library using Microsoft Excel

Hi all

I have a document library with CSV files uploaded. I have used the below mapping in DOCICON.xml present in \14\TEMPLATE\XML folder.

<Mapping Key="csv" Value="csv16.gif" EditText="Microsoft Excel" OpenControl="SharePoint.OpenDocuments"/>

And I modified mime type with "application/vnd.ms-excel" for csv in IIS7. Now, when i click on the file  popup is getting displayed with 2 Radio Buttons.

1) Read Only

2)Edit

When i select "Read Only", the file is opening in Microsoft Excel in readonly mode But when i select "Edit", the file is opening in Note pad and its editable.

Now, My requirement is to edit the csv file in Microsoft Excel not in NotPad.

Can Any one help me to acheive this!! Thanks in advance.