running git from non-standard location on Mac

Hi,

I wonder if someone could help me. I installed git on a Mac and then I copied the install somewhere else (which I do want to do, trust me).  I'm now having trouble with git svn. I'm getting "Can't locate Git/SVN.pm in @INC..."

I've added the bin folder to PATH. What else do I need to do? Do I need to use -exec-path=/MyPathToGit/libexec/git-core? How do I change the content of @INC?

Apologies if this is a dumb question, I'm not much of a unix man.

Cheers,
James