<p>Does anyone have any experience of developing external tools for SSMS 2005.  </p>

<p>Ideally I would like to be able to interact with the query windows directly, for example, taking the query text from the window to perform some processing on it.</p>

<p>Any pointers in the right direction would be great.</p>

<p>Thanks in advance</p>

Maybe this one will help
Microsoft Visual Studio 2005 Tools for Office 2005 Runtime (VSTO 2005 RTM)
The VSTO 2005 redistributable package installs the Visual Studio Tools for Office runtime, which is required to run solutions built using VSTO 2005. This runtime supports document-level customizations for Microsoft Office Excel 2003 and Microsoft Office Word 2003, and application-level add-ins for Microsoft Office Outlook 2003.