@jimken61....yes, that is one way of doing it....and you don't even need RSE for it...it can be accomplished with the RAW software that comes with your cam. It works well for shots that don't have an excessively  high range.

Visually, the results are somewhat more satisfactory but it does not however give you the latitude that the bracketing method (as explained by Onslow) does. Furthermore, be aware that not all RAW files are equal...some use a slight compression in their format...what this means is that the camera manufacturer has slightly reduced the bit depth when storing that sensor data to the RAW file.

Additionally, from the Photomatix site;

"Can't I just create the exposures from one RAW file? 
  Not really. Your RAW file contains data captured by the sensors for only one exposure. The total dynamic range you can reconstruct from one photo converted with different exposure settings can never be more than the dynamic range captured by your camera, and this is rather limited (see above).  
  When you are using only one exposure to capture the scene, your RAW file is already your HDR image. 
  Converting the RAW file to images with different exposure levels is a bit like slicing the dynamic range of the RAW into several parts. Combining back the parts into an HDR image will at best re-produce the dynamic range of the initial RAW file.  "

Working from a single RAW file will often give you a result that is more visually appealing...but really it does no more than selective curve adjustment and masking.

In youth, we learn....with age, we understand.