Question: How to make skills start at 1/2 of another Skill

[Lector]

Hello. This is neither a bug-report nor a feature request. I have a question:

I want to make a Skill that starts with Cthulhu-Mythos*0.5.
I already found out that i can link to skills using @item[...]
I also noticed that i can access the attributes using @dex
And i know how to make a link to a skill roll.

But how do i access the value of a Skill. This seems not to work obviously because i refer to the skill instead of the skills value:

Background: I bought the Dreamlands Book yesterday. And this book introduces 2 new skills. One of them (Dreaming) starts with Cthulhu-Mythos * 0.5. It would be nice if Foundry would always use the base of Cthulhu-Mythos even if Mythos goes up during the campaign.