Excuse a daft question... by why is it so special that an airline gives you an upgrade just because you're getting married, your birthday, your anniversary, your soon-to-be-something day?
If you can't afford it, well, make it up at your destination with flowers, gifts, little kisses etc. Or else see what you can exchange with someone who has EK miles to guarantee the upgrade.
But welcome to "Flyertalk" by the way.