OK, here is what I have seen. Take the part where you have your foregrip and screw in the expansion chamber. Then run the hose from the bottom line to the expansion chamber. Remember to seal the threads with teflon tape.
Heres a pic of what I am talking about. And again I'm not sure, just going by what I have seen. Try asking in the M98 Forum.
Just back into the sport after being out of it for five years....my how things have changed