How to get bone's original transform inside an animation sequence?

Hi, I’m currently working on my character’s animation blueprint with these features:

  1. I’m controlling the position of my character’s hand_l bone’s transform using [Two Bone IK] node.
  2. However, in order to calculate the effector’s position of my hand_l’s [Two Bone IK] setup, I will need to get the bone hand_l’s original transform of a given animation sequence.

As you may have noticed: since the hand_l bone’s transform will always get updated due to [Two Bone IK] node, may I know how could I get its original transform (before the [Two Bone IK] node’s effect is applied) inside its current active animation sequence?

Thank you!