Locking down Long Texts of Objects in Engineering Record

Gurus,

Please let me know is it possible to lock down the long texts of the objects attached to Engineering Record after the Engineering Record is closed.

I can make all the objects and columns inactive, but when I click on EDIT in the Engineering Record. The system gives the ability to modify the long text of the objects.

In Read Only mode its working it locks the long text,I need the functionality in EDIT mode as well for long text.

Kindly advice.

Thanks & Regards

Jo