boss

I have old Alibre 2011 expert and I have a problem. I need to make helical gear. 2D sketch is easy and I have tooth profile there. But my old alibre doesn't allow helical boss because it requires reference line. If it could use reference axis then it would be easy.

I have to put 4 drafted bosses in a part, and shell them for screws that are to connect it to a different part. Shelling keeps the wall thickness same and puts the screw where it needs to be. I can shell the drafted boss by itself, but it refuses to shell when in the part in any way. Not sure...