Add Alpe d’HuZes as an event

I’m training for the Alpe d’HuZes, but although it’s one of the biggest bike Dutch bike events, it’s not an option in the events list. So, I’m having to add it as a custom goal by multiplying the number of kilometers and elevation by how many times I’m planning on going up the mountain, but I feel like it’s not giving me an optimal training programme as a result.