In RFEM 5, you can add your own programs to the menu Add-on Modules → External Modules.
To do this, open the file "C:\Program Files\Dlubal\RFEM 5.XX\RFEM.ini" with a text editor. It is necessary to run the text editor with administrator rights.
The following three lines show how Notepad, the Windows text editor, can be inserted in the menu as an example:
ModuleName2=Notepad
ModuleExeName2=C:\WINDOWS\System32\notepad.exe
ModuleDescription2=Editor