No, compatibility wants that the latest version (r98) can open games made with older version (r95), but the newest version having a different code and probably more features than the older one, the older version can't comprehend and so open a project made in a newer version.
You could edit the number version in the xml files of the project, but you have to be aware that it could lead to bugs that can't be supported by Scirra (in other words, if something happen to your project it might get definitely corrupted and you would be on your own trying to recover it).
Also be aware that if your project uses some of the new features that are not part of the old version, no matter if you edit correctly the files or not, C2 might crash or worse.
Why do you want to downgrade to such an "old" version ?