Thansk to Chris Topping, a senior reseracher in ecological modelling at the University of Aarhus and CCPForge user for this tip.

Just for your information in case anyone else uses the same tools as me (MS Visual Studio and VisualSVN). With a little bit of fiddling around you can get VisualSVN to access the repository on CCPForge directly. This means that there is no change in the daily work routine. The way to do it is this:

1.  Check the code out from CCP forge into a working directory
2. Create a new solution using the working directory for all source files. If you already have a solution then remove each source file and replace it with the one of the same name from the /trunk directory of the working copy.
3. Add the solution to VisualSVN. NB I did not put the project files under subversion control because they may differ between developers and machines - but you could I suppose add these to /trunk too.
4. SVN commands from the IDE are now linked directly to CCPForge SVN for that project (just as if they were run from the command line in the working directory). You can see the URL in the subversion branch URL box.
5. Don't delete or move the working directory though, otherwise you need to do steps 2-4 again.