If your parents are not strongly opposed to your wishes, then it is not necessary to go through with the ritual. If it really upsets them, then it's alright to go through with the baptism as a favor to your parents. There's another point. Buddhism recognizes the power of the mind. If someone gives a sincere blessing, such as through baptism, then the receiver of the blessing will benefit. The blessing comes from the power of the mind of the person giving the blessing as well as from the power of the deity that the person believes in. Buddhism does not deny the existence of deities. Buddhism accepts that deities of other faiths do exist, and that they do have certain power. In the case of your child, if a Catholic priest baptizes your child, that is good for the child. If you want me also to bless your child, I would be happy to do so. Your child will be doubly blessed.