Allowing developer-specific settings in VS2008 Native C++ projects

Is it possible to combine the following properties, and if so, how?

• Store in our version control system some Visual Studio 2008 native C++ (VCPROJ) project files for the developers in our team that use this IDE.
• Allow some of those developers to tweak their projects (e.g. using debug version of third-party libraries instead of the usual ones).
• Make sure these modifications are done in files that are not versioned.

In other words, I would like to allow developers to tweak some settings in their projects without risking that these changes are committed.

An 'optional VSPROP' file approach seems doomed to fail, as VS2008 refuses to load projects that refer to non-existent VSPROP files...

Any other suggestion? Is this possible with VS2010?

You may not be able to do this but using a solution that generates the vcproj like CMake for example would let you do this. Scripts all your project with CMake and literally conditionally include a config file(if present for example) that developers can change on their setup.