Add custom Font Icons to my themes Elegant Icon font pack

Hi, My WordPress theme has a "Side Area" that I am turning into a "User Menu" navigation. If you are in the backend of my site, you'll see my themes options "Edge Options" (I am using the dorian template by edge themes) Anyways, when you go to the themes options there is an menu called "Side Area" inside that options there is a Drop Down menu allowing you to select what Icon Pack and Icon you want to use for the "Side Area" icon. Right now it is a plan "Hamburger" icon, I want to change it to a different icon. What I would like is, I want to add some custom font icons to the already existing "Elegant Icons" When you go to my sites theme options "Edge Options" and then click on the "Side Area" menu, there is a dropdown menu allowing you to select your icon pack (I want to continue to use the Elegant Icon pack) The Icon that I want to use is not listed in the dropdown menu of icons. So what I need is for you to add some custom icons to an already existing Font Icon Pack which is called (Feather) you can find it in the icomoon app site. If you know how to add font icons to an already existing list of font icons. This job is for you! :) Please post your bid, and PLEASE do not bid unless you are 100% confident you can do this project and that you have worked with this type of coding before, If you need further information like screenshots please let me know. Thank you, Jon