btMatrix3x3::setEulerYPR ( const btScalar & yaw,
const btScalar & pitch,
const btScalar & roll
So I'm assuming you could use that to create a btMatrix3x3, and then apply that to a btTransform's origin that can be applied to the btRigidBody.
If someone could update the two commented lines with the appropriate code, it will be exactly what I want.
No one is here to just write your code for you. You're explicitly asking people to do that. Try and have a little courtesy, it's a forum for information sharing, not task orders.