Unfortunately, I couldn't manage moving my player pawn's hand in an acceptable way. I've tried many combination of different bone amounts, maximum angles and some other parameters, but I couldn't get a satisfying result.
I couldn't find a b_RightWeapon bone in my CH_AnimHuman_Tree, so I tried tieing the SkelControl_CCD_IK (labeled 'RightArmIK') with some other bones, but none of them worked like the way I wanted. All the difference between what I do and told in the tutorial is the bones connected to the RightArmIK. I would greatly appreciate that if someone would give me any idea about which bone should be attached to our RightArmIK in the new version of UDK and what their parameters are.