I think i found what your talking about while i was having a look.
If I recall, what you say is the radio message ID never changes...
Maybe I didnt do things correctly though
Anyway, attached is the source and compiled plugin for use.
It will allow custom sounds for grenades - but not text.
Check out the source code to see the CVARS to configure the plugin
what you need most for now is:
Code:
FNH_sound_flashbang "ambient/animal/horse_5.wav"
FNH_sound_smokegren "ambient/animal/horse_4.wav"
FNH_sound_hegren "ambient/animal/horse_3.wav"
Here is where i got up to: