title: Setting Vim Options with Variables
body: <p>I've a question that should be fairly simple, but I have yet to find a solution for.  I'm editing my .vimrc and would like to set an option using results saved in a variable.  For example, I would like to aggregate all my temporary files in ~/.vimetc.  Here's what I would like to do,</p>
  
  <pre><code>let s:vimetc=$HOME.'/vimetc/'
  set backupdir=s:vimetc.'backups/'
  set directory=s:vimetc.'vimswap/'
  set viewdir=s:vimetc.'vimswap/'
  </code></pre>
  
  <p>Of course, set doesn't resolve variables so I just end up with the literal |s:vimetc.'backups/'|, not at all what I would like.  I tried using &amp;s:vimetc with similar results.  Does anyone know how to do this?</p>