create animated sequence from base character

Hello guys !
I’d like to make custom animation sequences in persona for my character. For instance I’d like to create a sequence where my character swings his sword that I would then trigger each time the player hits the attack key.
Since there is a skeleton I believe there is a way to tell ue 4 to move a specified socket between frames, a bit like one can set position in matinee for instance, but I can’t find where.
Is there actually a way to do so ?

On the same principle, is there a way to change keys of the basic animations form the starter pack (say i want to change the character’s hand orientation while he is running for him not to cut his own leg with the sword) ?

Thanks