title: teamcity dynamically add or change parameter in build step
body: <p>i am trying to using teamcity to watch then auto build/test a set of branches within a main folder,so i set up a build configuration in teamcity to watch a main folder which include many branches of the same project,once there are new commit in one of those branches, teamcity will call a .bat file in first build step to generate some parameters then return that branch URl which has new commit, then compile/run unit test only in that branch.</p>
  
  <p>my trouble is i don't know how to pass this URl return by that .bat file to the next build step, what i consider is to set this URL into a configuration parameter using following statement in command line runner.</p>
  
  <pre><code>%##teamcity[setParameter name='subpath' value='getsubpath.bat %otherparameter%']%
  </code></pre>
  
  <p>unfortunately this code do not occur any error and do not set a new parameter name 'subpath'.</p>
  
  <p>is that i am using this 'setParameter' statement incorrect? or it is not available in command line runner. any one can give a example of using ##teamcity[setParameter.....] or some idea about this scenario？</p>