Convert RSA XML to openSSH Format?

Question

I've used the .Net class RSACryptoServiceProvider to get a keypair:

using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())
{
  File.WriteAllText ("PublicKeyOnly.xml", rsa.ToXmlString (false));
  File.WriteAllText ("PublicPrivate.xml", rsa.ToXmlString (true));
}

Now, I would like to use this with openSSH, but the key format looks nothing alike. Does anyone know how to convert both the public and private keys to files that openSSH can use?

Thanks!