How to attach Bone/mesh to another bone within the same Skeletal mesh?

I have a rigged character that was provided to me. And they come with an item/accessory on its own bone, existing within the same character skeletal mesh. Like a microphone placed at their feet. I have some mocap animation, but want to know how I can attach that Mic(that is also part of the whole characters own skeletal mesh) and attach that to the same character’s hand. I am only animating characters within sequencer, and there is no character BP or anything.
I know how to do this if they were separate items , like using an “Attach” Track in Sequencer, but not when they exist within the same skeletal mesh asset. How do you go about doing this? Appreciate any help.