Someone in Poser forum finally explained the use of Winzip in a manner that I understood. Currently the Winzip extension is .zip, but if you change that extension to .gz Winzip will unzip it. I'm really dense when it comes to learning new computer related stuff, and I still don't get how you access the above script to uncompress a single file within Poser. Changing a file extension and using Winzip is do-able for me and within my comfort zone too. I'm not at all comfortable with "scripts", frankly they scare me. Especially ones that are named after giant snakes :P

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi