title: What's currently the best way to extend Excel using C#?
body: <p>I have the professional versions of VS2008 &amp; VS2010.</p>
  
  <p>I wish to add a couple buttons to a toolbar in Excel. When they are clicked I'd like to be able to open a form (either WinForms or WPF is fine)  collect a few values from the user in the form and then take that data + read cell values from the current worksheet to perform some database operations.</p>
  
  <p>What's currently the best way to do this using C#? I'd greatly appreciate a pointer to any examples / tutorials. My understanding is that VS2010 has improved the process alot but I may have to deal w/ Excel 2003 which I don't think it supports.</p>
  
  <p>I get confused between Visual Studio 2008s Extensibility->Shared Addin template and other Office Addin templates I've seen. I'm not sure when which type of solution is appropriate.</p>
  
  <p>I'm new to Office development so I'd really appreciate any help to get me going on the right track.</p>
  
  <p>Thanks much.</p>