title: Customizing the output of Perforce RCS keyword expansion
body: <p>I'd like to filter files using RCS keyword expansion so that instances of <code>$Change$</code> are translated to <code>1745</code> rather than the default behaviour of <code>$Change: 1745 $</code>.  I realize that this would prevent future expansions, but that's acceptable for the purposes.</p>
  
  <p>Other methods of inserting the changelist number into a file are also welcome.  This is the only method I've seen with Perforce that works during submission -- it's just that I'd like to clean it up so that it can be cleanly inserted into version numbers.  Could this also be accomplished with triggers?</p>