Contrary to the currently prevailing opinion, and while it may not be “best practice” to not use the in-game compiler, you can compile models for NWN EE with nwnmdlcomp. You just need to have 1.69 installed somewhere on your system.
EDIT - Also make sure the model has less than 17 bones. If it has more than that, compile it with the in-game compiler. Just be sure to save a copy of the ascii somewhere in case you need to edit the model in the future.
I bring this up because while browsing the latest iteration of CEP, I noticed quite a few models that were not compiled. Typically, these were models that used custom animations housed in a supermodel that is not in the base game assets. Well, you can compile these too 
What happens when you get the “ERROR: Supermodel not found” message? Well, it’s an easy fix.
What you need to do is put EVERY single custom supermodel (or any modified model used as a supermodel for another creature) in whatever folder you put nwnmdlcomp into. Nwnmdlcomp will check its root folder first, then the 1.69 base game install, then, if the supermodel still isn’t found, it will throw the afore mentioned error.
EDIT2 - if compiling a chain of models that use a member of that chain as a supermodel, you need to compile the entire chain at the same time.
If you could see my nwnmdlcomp root folder, you’ll see that every supermodel in the game and my content is in that folder.
You can get a list of supermodels off the WIKI at Creature BASE Models - Neverwinter Nights 1: EE - nwn.wiki