If you actually just want to use these pages as one-pager / landing-pages (as the url 'landing' suggests) it could also be done by adjusting your domain settings for `abcd.com` and `efgh.com`. 

At least with my webhost I can adjust where a domain would look for its content. Setting the 'home' path to `/landing/abcd` (or actually seting the 'A-entry' of the dns registry accordingly) would do the trick on the server I'm working on – at least when all three domains share the same webspace.

So you might also consider asking your question over at [stackoverflow.com][1] or [webmasters.stackexchange.com][2] since it could be a more technical question. 


  [1]: http://stackoverflow.com/
  [2]: https://webmasters.stackexchange.com/