Please title your threads more accurately to reflect what the thread is about. If you're asking a question, putting the question in the title helps. This will help out people later on if they have the same problem and run a search through the forums.
Now, onto your question. Scripting won't be able to achieve what you desire, however, you can do it.
Open up the setup.ini file and change the keycodes used for crouching and jumping to 0. (I'm not sure which of the configkeys in the setup file are for those, so you may want to compare the value with a keymap to find out) That will disable them permanently. Hope that helps you out.
The one and only,