After the generated code has been inserted into the program window, HDevelop internally keeps the code linked to the corresponding assistant. This link is kept until the assistant is quit using the menu entry File ▹ Exit Assistant. If you close the assistant by using the menu entry File ▹ Close Dialog or the close icon of the window, the assistant can be restored from the top of the menu Assistants.
You can change the settings inside the assistant and update the generated code accordingly. The code preview will show you exactly how the generated code lines will be updated. Furthermore, you can delete the generated code lines, or release them. When code lines are released, the internal link between the assistant and those lines is cut off. Afterwards, the same assistant can generate additional code at a different place in the current program.