title: Set property value based on condition in WiX
body: <p>I searched through several questions at Stack&nbsp;Overflow, but nothing helped me. The problem is:</p>
  
  <p>I look in the registry for some value (I know how to do that). I know how to set property. But I cannot find the way how to write this expression in WiX. This is what I want to write in pseudocode:</p>
  
  <pre><code>if(registryvalue contains substring1)
      set property to value1
  if(registryvalue contains substring2)
      set property to value2
  </code></pre>
  
  <p>This condition must be evaluated at runtime. Is there a way to write this condition? What would some sample code look like?</p>