What is a non-alcoholic substitute for rum in a glaze? I want to make an orange cake and its recipe calls for rum in the glaze. Rum, anything alcoholic, rum extract, etc. are not an option for me. Is there a way to substitute with vanilla extract? If so, in what proportion?

According to the recipe, for glaze we need:


½ cup strained fresh orange juice
1 Tbsp. unsalted butter, melted
2 Tbsp. dark rum
1 cup confectioners' sugar, divided 


I have looked at the answers to What is substitute for rum in baking?, but they focus mostly on dough/batter and aren't very specific about method of proportion.
The rum is just for flavor so you can skip it entirely if you like, just make up the liquid with more orange juice. If you want to use vanilla, just try 1/8 - 1/4 tsp. If you'd like the flavor of rum without the alcohol, non-alcoholic "rum" does exist (spiced rum here, which would be nice with orange). Non-alcoholic "Liquors" Just in case you'd like to know, these products are Halal certified. Halal Certificate