Ok can be done but will still need two 12/3 romex to center box for 4 way with one coming from hot/switch box and the other going to the outer 3 way, The nuetral or white wire from the 12/3 going to center box will pass completely thru to last 3 way where it becomes the "common" and will be used as light switch leg at 1st box. In both 2nd and 3rd box the red and black are travelrs and will hook to switch as marked. Those boxes are done. Now at 1st box the red and black are travelers to 3 way switch and hooks black power from 12/2 to the common post on switch. Now the white wire from 12/3 ties to the balck from light box itself and caps off, and push back into box. All grounds wires cp aoof together and push back into boxes and install sitches and turn on powre and you should be set
