Convertible Preferred Spreadsheet Calculator

I need an excel spreadsheet that calculates the total return for a convertible preferred equity security based upon a coupon and a convert price that is driven by the change in price of the common equity. I want to be able to input target all-in return, convert coupon and change in common equity and have model tell me convert % and the total convert return. Feel free to construct the model using your expertise in the likelihood I've shown my lack of knowledge in the security.