You'll find that smoked paprika is also available in mild (dulce), semi-hot (agridulce), and hot (picante) varieties, so you can definitely use it as a substitute for hot paprika. Like cayenne pepper powder, it can enhance the flavor and aroma of your dish because of its distinct smoky flavor.
So, how can you substitute chili powder for paprika? Well, I can't really give you a standard substitution ratio. It's best to add it gradually, give your recipe a taste, and then adjust accordingly.