// init targetPed somehow
// We create a vector pointing from the player to the target ped
Vector3 aimVec = targetPed.Position - Player.Character.Position;
float forceMultiplier = 10f;
targetPed.ApplyForce(aimVec * forceMultiplier);
This creates the push effect, though you don't have the particle FX, obviously.
IIRC someone already made something like this, dunno who.
Hardest thing would be finding what ped is being targetted, though that's not too hard either.