EDIT: If you're looking to change a specific comp.screen dialog in-game, then you have to find the name of the module you are in (by typing "whereami" in the cheat console), then go to kotor tool (can be found here:
http://kotortool.starwarsknights.com/), choose RIMs, then your module, then open the dialogs section and open up the dialogs until you come across with your comp.screen's dialog. Then open DLGEditor (
http://www.starwarsknights.com/mtools/dlgeditor_232.zip) and make a new dialog file. Save it as the name of the original comp.screen's dialog. Then, put that file in the override. Should work just fine!
How to make the new dialog file? -> Use the dlg editor to make the wanted entries and replies:
Entry: What the screen will say before you reply
Reply: What you choose in the comp. screen
In each reply you can attach scripts to make things happen.
Quite simple. This comp. panel should be in the placeables list of the .git file of your module. Open it up in Ktool, and in dialog, enter the name of your .dlg file. Then, open up DLGEditor and use it to make the wanted entries and replies.
Hope I helped !