title: Can we get the image that is not in front by DM script?
body: <p>I have questions regarding dealing with multiple images of a series: </p>
  
  <ol>
  <li><p>When we are coding, we can get the front image by 
  <code>image front:=GetFrontImage()</code>. Can I also get the image that is not in front?
  For example, if there are total 20 images, can I directly get the 7th image (-Counted from front to back-) by something similar to this pseudo-command:<code>image img7:=GetFrontThe7thImage()</code> ?</p></li>
  <li><p>I have a series of images, the format of names of images are consistent, such as the name of front image is xxx001, the second is xxx002, the third one is xxx003,..., the Nth image is xxxN, 
  Could I use a coding define like <code>image N:=imagexxxN</code>, and then I directly use image N for math process? Or should I use a loop and get the images one-by-one?</p></li>
  </ol>