Hey there @Stereomono9! Welcome to the community! The technique you’re looking for, is hand inverse kinematics, IK for short. This will allow you to control the location of each hand via script and handle the elbow position realistically with the IK solver. Some of these resources should help with the process.
Thread with some solid (but older) resources:
A video going through a climbing system utilizing hand IK positioning:
An explanation of Two Bone IK:
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