How to make a perk strength scale with a global variable instead of a static number?

[Ridenberg]

I'm making my first ever mod that allows the user to tweak power attacks' damage and stamina consumption, it's handled through use of a custom perk which is distributed to all characters.

I want to integrate MCM into it, so that player can choose their preferred modifier. My MCM script can already write down the value that player chose through a slider, as a global variable. But how do I make the perk actually use this variable instead of a static number?

In other words, how do I make something like image below, but using my custom variable instead of a static number?

[dylbill]

This will require skse. There’s SetNthEntryValue and GetNthEntryValue script functions with skse. 
 

https://ck.uesp.net/wiki/SetNthEntryValue_-_Perk