title: Dynamic variable names in SAS
body: <p>Is there a way in SAS to specify dynamic variable names in code? 
  i.e. use different variables on different observations based on the value of another variable?</p>
  
  <p>For example, my input data set could be:</p>
  
  <pre><code>Index  Var1   Var2  Var3
  1      78.3   54.7  79.8
  3      67.2   56.2  12.3
  2      65.3   45.2  98.1
  1      56.2   49.7  11.3
  1      67.2   98.2  98.6
  </code></pre>
  
  <p>And I want to add a column that holds the value of Var*Index*.
  i.e. the output I'd want would be:</p>
  
  <pre><code>    Index  Var1   Var2  Var3  Var_Index
      1      78.3   54.7  79.8  78.3
      3      67.2   56.2  12.3  12.3
      2      65.3   45.2  98.1  45.2
      1      56.2   49.7  11.3  56.2
      1      67.2   98.2  98.6  67.2
  </code></pre>
  
  <p>I'm unable to use <code>call symput</code> to get this to work. Also I should mention that my real problem is slightly more complicated, and I already have a messy brute force method but I'm looking for something clean.</p>