Either
-create something like a jump cycle (as you can see in the 3rd person template) -> when the player presses W+Jump the character will move forward, otherwise he will stay where he is. Depending on how exactly you want to implement your jump attack, you can also let him always move when you play the jump (e.g with a “set velocity”)
-or use a root motion animation -> then the character will stay at the landing position. 
https://docs.unrealengine/latest/INT/Engine/Animation/RootMotion/index.html
Probably there are other ways, but those are the ones that came to my mind 