In order to reuse your WebFOCUS-Code, you can run a already existent WebFOCUS-script (.fex) within another script.
Just use the -INCLUDE keyword and specify the filename of the script you want to run.
Sample code:
-INCLUDE myscript.fex
Note the - character before the INCLUDE. The script has to be located in the same directory as the script which is activating it.