The Bioware scripts aren't all in one folder, but you can easily make one.
Using NWNExplorer, navigate to NWN Main Data > scripts.bif. Place the cursor on the Scripts heading, right-click > Export to your folder.
Repeat for SoU, HotU, HotU patch and 1.69 patch, in that order. The patches don't have a scripts.bif - simply export from the Scripts heading.
The order is important - you want expansions and patches to overwrite the OC in the correct sequence, so that you end up with the latest scripts.
If you don't have a tool that does text search within a folder, I recommend FreeCommander.
This approach excludes campaign-specific scripts, since most modders never use them.