As far as I know, there is no standard way to accomplish this.
But you can run the command svn status myproject
where myproject
is the folder of your working copy. It will returns information about the files you have modified. This information includes the paths of those modified files so you can parse the paths using a script (or an application) and copy the them to another location.
After that you can delete myproject
and do a re-checkout using svn checkout repositorypath myproject
where repositorypath
is the repository path of your project.