Hi
I have the same problem, how can we solve it?
If we could use php this solution would solve the problem:
add_filter('woocommerce_get_checkout_url', 'wpse_redirect_checkout');
function wpse_redirect_checkout($url) {
global $woocommerce;
$checkout_url = 'https://domain.com/checkout/?parameter=DINAMIC_VALUE_IN_PHP';
return $checkout_url;
}