Re: Where do I go to find just a remote for this exact model Roku?
Only remotes from Roku sold at walmart have the vudu key. The only separately sold roku remote at walmart now is wifi voice remote, but it won't work on your 3700 express which only takes IR remotes. Look on ebay for Roku remotes with vudu key, make sure it doesn't have a tv power button at the top of the remote, that means its a Roku tv remote and won't work at all on your express.
You can purchase the One-For-All urc-7935 streamer remote at walmart, it will have a vudu key. Cost about $25 plus tax. Or you can found open box all over ebay for $10.