svn copy problem Follow

Im trying to execute an svn command from a teamcity build step but Im getting an error



ive tried 2 svn command executables (both give the same error)

C:\Program Files\SlikSvn\bin\svn.exe

C:\Program Files (x86)\CollabNet Subversion Client\svn.exe

and these are the command line parameters

copy https://servername/svn/code/trunk/src https://servername/svn/code/branches/Code_QA Username=user password=password Arguments= –non-interactive –trust-server-cert

but I get this error

svn: Cannot mix repository and working copy sources

I then used a Tortoisesvn client and created the branch manually, which worked. I need this to work as a teamcity build step, anyone got any idea where im going wrong ?