Can a customary marriage become statutory?

Dear Harold,

This column recently highlighted differences between customary and statutory marriages. I am shocked that in customary marriages, there is a silent provision that a man can be adulterous but not the wife. It is also potentially polygamous and gives husbands the leeway to chastise their wives. My husband may be privy to these provisions as he finds it difficult to keep his zip up. I fear contracting sexually transmitted infections from him as a result of his philandering ways. I want us to have a statutory marriage so that in case he is adulterous, I can file for a divorce. How do I go about it?