Write the contents of a .conf file into a variable located in a separate .conf file

I am configuring my hyprland.conf file and I am attempting to do it in a clean and modular fashion. I am trying for a modular fashion so that I can share my dotfiles and someone else can change which components they are using without directly modifying the hyprland.conf file. Near the top of my hyprland.conf file I would like to create variables for use in other parts of the file, such as the keybindings. If I explicitly set the variables, such as $terminal = kitty, they work fine. However, when I attempt to populate the variable with the contents of a separate .conf file, it doesn't seem to populate. The terminal.conf file that I am attempting to retrieve the contents of contains only the following: kitty The code I am using to populate the variable in my hyprland.conf file is as follows: exec-once = export TERMINAL="$(cat ~/.config/hypr/settings/terminal.conf)" If I open a terminal and enter echo "$(cat ~/.config/hypr/settings/terminal.conf)" I get kitty as a response, which is what I am expecting to see in the variable. For the keybinding section of my hyprland.conf file, I am attempting to use the variable as follows: bind = SUPER, T, exec, "$TERMINAL" However, when I use that keybind to open a terminal, nothing happens. Therefore, I attempted to check the contents of the $TERMINAL variable in my hyprland.conf file by executing the following command: exec = echo "$TERMINAL" >> ~/.config/hypr/hyprland.conf All it adds to the file are empty lines. What am I doing wrong?