This is some vector math you need to apply. If you’re not familiar with it, I would suggest to download the Content Examples project from the Marketplace and check out the Math Hall level. You could also read up on the matter here.
If you want to move an object in a certain direction, you need to get a vector that points in that direction. The vector that gives the direction from position A to position B is the difference between these positions: B-A. You’ll need to normalize this vector to get a unit vector (a vector with length 1). Now you can multiply this direction vector with a scalar (say 200).
The result will be a vector pointing in the right direction and having the correct length. So you just have to add it to your starting position (your object’s current location) to get the new position.
I hope this helps. Applying this to BP shouldn’t be too hard. There are nodes for each of these operations (vector subtraction, normalizing, multiplication). Let me know if you’re still stuck.