How to redirect example.com/url to www.example.com/url using HipHop VM

Question

How do I redirect example.com/url to www.example.com/url using HipHop VM. I'm not sure where to begin with since the rewriterules section seems to only apply pattern matching to the path

I've tried

RewriteRules {
    rootdomain {
      pattern = *
      to = http://www.example.com
      qsa = false
      redirect = 301

      conditions {
        * {
          pattern = ^example.com$
          type = host
          negate = false
        }
      }
    }
 }