Automated Managed C++ wrapper?

I have a very large project (100,000+ lines) which is written entirely in unmanaged C++. I am looking to add some nice GUI and web service front ends to the project, so I want to convert the code to managed C++. I've never tried to do this before, and have been reading up on some of the articles here on how to make wrapper classes. From what I've seen, it seems the code to wrap classes could be auto-generated easily. Are there any tools to do this automatic wrapper generation?