You edit the files in the scripts folder. If you have a script and want to add it, just make a subfolder in scripts and put the files there.
The files you edit are .pas, writen in pascal. If you want to make a new script, you can just create a .pas file with all the code and a file called Includes.txt, where you write the script file name.
For example:
scripts
|_default
|_your_script_folder
|_script.pas
|_Includes.txt
In that case you should write script.pas inside includes.txt.
In
http://enesce.com/help/ you can find the documentation you need to write a soldat script. (All the events function, etc)