Rig an arm that is not modeled in T Pose

[Caveman]

Hi, the hands in my model are not modeled in a T stance, is there a way to make a non orthogonal working IK joint? The included curve shows where I would want to put the joints. The curve runs right through the center of the arm geometry.

The Curve starts from the shoulder and each CV determines where each joints need to be placed. I was planning on a split joints biceps elbow and forearm setup.

Thanks for reading.

Any help would be much appreciated.

Regards.

[Caveman]

Well I was thinking I could create the joints the normal way and use Chain Up Vector to align the joints to the geo hands before enveloping. That actually worked but is there any other way, I am really curious?