You can edit nwnplayer.ini so that you can edit the Bioware campaign modules earlier by making sure that file has the lines
CODEWORD=hacktastic
CODEWORD XP2=barkeater
CODEWORD XP1=ffrodriguez
Also, see Lightfoot8's comment above.
Also, you can edit M1Q0EFentEND.nss to change how XP is given at the end of the prelude (in the stables).
Have fun modding the BW campaigns. I would guess that's how most people get interested in NWN modding (at least for coding). IMO, changing things so the campaigns are harder makes them more fun.