In the meantime, I stumbled across a recipe for making Cherry Limeades at home:
Sonic Cherry Limeade
1 12 oz. can Sprite
3 lime wedges
1/ cup cherry juice
1. Fill a 16 oz. glass 2/3 full with ice. Pour Sprite over the ice.
2. Squeeze the lime wedges over the drink and then drop them in.
3. Add the cherry juice and stir briefly. Serve with a straw.