Show us some pictures of the wheel damage.
If it's not too bad at the valve stem hole it's not too difficult to patch the metal. Do you have a wire welder or access to one? Sometimes you can take a flat washer that fits over the valve stem and weld it to the rim and fill in as required, grind smooth and have a wheel that will be fine. Or, you can patch the entire area where the rust is and drill a hole for the valve step in a different location.
If it's not too bad at the valve stem hole it's not too difficult to patch the metal. Do you have a wire welder or access to one? Sometimes you can take a flat washer that fits over the valve stem and weld it to the rim and fill in as required, grind smooth and have a wheel that will be fine. Or, you can patch the entire area where the rust is and drill a hole for the valve step in a different location.