The sourceforge package is old and syntax (the way instructions are called has changed with Gimp 2.8)
Is this the one you are looking for.

An updated set of scripts, although not all of the sourceforge set, updated for Gimp 2.8 is available on Paul Shermans site
http://www.gimphelp.org/script28.shtmlRenamed but the above example is FU_create-new_glass-text.scm
FWIW, my advice do not put the script in
C:\Program Files\GIMP 2\share\gimp\2.0\scripts
but use your Gimp profile
C:\Users\YOUR-NAME\.gimp-2.8\scripts