Spotted this while looking for other stuff. Looks like it might come in useful at sometime. However someone else out there might find this to be 'just what is required' now. so here it is:

DefaultPrograms is a small, free utility that can manage and edit the way windows works with filetypes, such as editing their context menu items, their icons, description, and the associated file type for an extension. For Vista and Windows Seven it can also manage and edit autoplay handlers, as well as edit, add, or remove the default registered programs associated with file types...[
Note: Microsoft .Net Framework 3.5 must be installed. This is a required prerequisite. It is freely available from for Windows XP and Windows Vista users who don't have it.

Download: Default Programs Editor

Program Information: Default Programs Editor