title: How to manually define a variable in Zebra Programming Language? (ZPL)
body: <p>I'm programming in ZPL and I need to define a variable manually. A simple Hello World Example:</p>
  
  <pre><code>^XA
  ^FO,20,10^ADN,40,25^FDHello World^FS
  ^XZ
  </code></pre>
  
  <p>I want to be able to:</p>
  
  <pre><code>SET $HW$ = Hello World
  ^XA
  ^FO,20,10^ADN,40,25^FD$HW$^FS
  ^XZ
  </code></pre>
  
  <p>I read the Zebra documentation and it talks <strong>only</strong> about its use in ZebraDesigner Pro, but I must define it with code, not with graphical mode. And the variables like <code>$CODEDATA$</code>, <code>SVERSION$</code> are not working automatically here. Then, how can I define a variable in ZPL? </p>