Retargetting animations from unity 3d into UE4

I have about 100 animations that ive been using in the unity mec systemt hat i xfered from maya into UE4

so the animations only work on the character i made the animations with

my question is how can i actually retarget the character skeleton with 100 animations onto the herottp mycahracter

also can UE4 control masking in unity all i had to do was copy my script onto different skeletons.