title: How to increment character data type in Ant script?
body: <p>Example:</p>
  
  <pre><code>&lt;project name="num" default="jav"&gt;
    &lt;taskdef resource="net/sf/antcontrib/antcontrib.properties"/&gt;
    &lt;!-- IF and Conditional task inbuild taskdef  --&gt; 
  
    &lt;target name="jav"&gt;
      &lt;property file="proper.properties"/&gt;
      &lt;math result="index" operand1="${index}"
         operation="+" operand2="1" datatype="int"/&gt;
      &lt;echo message="index=${index}"/&gt;
      &lt;echo file="proper.properties" message="index=${index}"/&gt; 
    &lt;/target&gt;
  &lt;/project&gt; 
  </code></pre>
  
  <p>In <code>proper.properties</code>, I have that <code>index=1A</code>. I'm able to increment the integer part but not character part.</p>
  
  <p>I have one variable <code>index=1A</code>. I want to increment this number after each build process. </p>
  
  <p>Suppose I have done the first build, then it should be <code>index=2B</code>. That is, I want to increment the integer as well as the character value (<code>1A</code>, <code>2B</code>, <code>3C</code>, ...) in Ant script.  </p>
  
  <p>Is this possible in Ant?</p>