Can someone tell me what exactly I have to type in the command pane to have never ending missile launcher?

I have pulled up 5 or 6 websites and they DO NOT TELL YOU what to type!

Maybe there is no such cheat?

↑↑↓↓←→←→BA

The Neverending Missile Launcher doesn't exist in the codes. Just a Missile Launcher with the Neverending effect added to it. Drop a Missile Launcher and click on it while in the command pane attachmod 1cc2ac. Personally I prefer attachmod 1cc2ad since IMO Two Shot is better for Fat Mans and Missile Launchers.

Getting the Legendary Modification mod is easier due to not bothering with having to drop the item, click on the item, then find the appropriate code. Also, there might be some problems with the command not working properly due to clicking on the wrong thing on the ground.