As I mentioned in my previous post you can override the default behavior of the “Show Quoted Message” link.
You need to create a custom list template, it is very easy with Visual Studio 2008 and Visual Studio Extensions for SharePoint Services (VSEWSS) 1.3.
I will explain all steps from scratch.
After a successful deployment open your site collection and in the create page you will see your new customized list.
Be aware that when you edit your reply, this modified discussion board will show the original reply since you’ve edited the “Quoted Message” while the original short reply is in a hidden column. So the modification will only show up if you click the link. So keep in mind that this implementation has limits.