title: Reporting Services column visibility expression includes substring column names
body: <p>I have an SSRS 2012 report with columns that are to displayed or hidden based on user parameter selections.  Each column has a visibility expression associated with it.  For instance, the expression to show or hide the "Cash Flow" column is:</p>
  
  <pre><code>=IIF(InStr(JOIN(Parameters!IF_Variables.Value,","),"CashFlow")&gt;0,False,True)
  </code></pre>
  
  <p>The problem is that I also have a column called "AnnualCashFlow", with a corresponding visibility expression.  If the users selects it, the "CashFlow" column will also be displayed, even if it wasn't chosen, because it is a substring of the longer column name.</p>
  
  <p>There are several other columns that are related in this way.  How can I formulate an expression that will only find the exact string requested?</p>