PreUpdateAnimation event?

I have a stupid question. All my animation in AnimGraph converted to “one frame animation” and driven by variables from AnimBP.
Desred position for each anim calculated only if the animation have non zero weight in AnimState. When animation becomes non zero weight, desired anim position value taken from the previous frame, but this value is wrong because is not caclulated if anim have zero weight (this value from last non zero weight frame). I think a additional events for anim bluerpint (like PreUpdateAnimation http://api.unrealengine.com/INT/API/Runtime/Engine/Animation/UAnimInstance/PreUpdateAnimation/index.html) can help in this situation. How create this function in visual studio? If we know other variant to solve this problem, say please. Sorry for my English!