Hello and thank you for the answer.
Yes, I did change the keyboard language to English (in this case, the keyboard is QWERTY).
Casting spells in such case is good, due to spellbar using QWERTY binding.
Nevertheless, I am used to write with AZERTY so when messaging someone, this is messed up.
Anyway, I think that the only solution possible at this point forward is having the feature of custom mapping directly in NosTale or maybe having a third option when changing the binding using AZERTY instead of QWERTY.