BIMMERKID2, I have no idea if it's possible or not. Here's what I do know: even if it IS possible, you have a very good chance of dealing with check-in staff who either don't know how to do it, don't want to do it because it's more work, or can't do it because of some unforeseen computer glitch or datalink being temporarily down. IMHO, when you are interlining between carriers that you know aren't that well integrated you HAVE to assume that you aren't going to be able to be checked in all the way.

Even between NW and KL, a transfer I've seamlessly done more times than I care to count over the past decade, I've still had to occasionally pick up boarding cards at the transfer desk in AMS or WorldClub in DTW/MEM/MSP.