a) First, the wave files need to be in the correct format (not sure which one though). Check to be sure.
b) Open up XCC Mixer, then click Launch => XCC Sound Editor
c) Drag and drop your wave files in there.
d) Check your RA2/YR directory, and you should have an audio.bag and an audio.idx. Keep in mind that audio.bag will be quite large and will greatly increase the size of your mod.
e) in Sound.INI, create your [xxxxxx] section, and create a Sounds= under it, as well as any other options you would like. Then list your sounds without the .wav ending. Since they are voices, they need a "$" to indicate that they are a "string" (which means that the sound consists of a string of words, characters and numbers, hence the name). Seperate sounds with a space.
The smarter (sorry Xgamer ) way is, to use XCC Mod Creator; it will just include the new sounds, and generate the required audio.bag & .idx on the player's computer – this way, you avoid including a 17 Megs audio file...
EDIT: Whilst this is only a different way of "supplying" the sounds...you still have to write the required .ini entries.
hmm...since they give additional information on how the wav files of RA2 should be, I doubt it...but you better ask someone else, since I've never tried that...
BUT: In the end, it would have no use at all...in the moment Mod Creator "creates" the mod on the user's hd, it would convert them to the deezired format...