You will need a controller keyboard with a breath controller input,
or get the BC3 to MIDI convertor and plug it into a midi interface.
I use a CME UF8 and it has the BC input.
I use the BC3 and I assign it to Vel XFade or Expression or
both depending on the patch and music.
It took a while to get used to it and for some its impossible to use
but I like using it for volume swells and for that alone it is worth it to
me. I can do complex dynamic changes much easier than with the mod
wheel or drawing it in the piano roll.
Hope that answers your questions.
DM33